ADM8691ARUZ [ADI]

Microprocessor Supervisory Circuit;
ADM8691ARUZ
型号: ADM8691ARUZ
厂家: ADI    ADI
描述:

Microprocessor Supervisory Circuit

文件: 总24页 (文件大小:384K)
中文:  中文翻译
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Microprocessor  
Supervisory Circuits  
Data Sheet  
ADM8690/ADM8691/ADM8695  
FEATURES  
FUNCTIONAL BLOCK DIAGRAMS  
Upgrade for the ADM690, ADM691, ADM695 and  
for the MAX690, MAX691, MAX695  
Specified over temperature  
V
BATT  
V
OUT  
Low power consumption: 0.7 mW  
Precision voltage monitor  
V
CC  
RESET  
GENERATOR  
Reset assertion down to 1 V VCC  
1
RESET  
4.65V  
2
Low switch on resistance: 0.7 Ω normal, 7 Ω in backup  
High current drive: 100 mA  
Watchdog timer: 100 ms, 1.6 sec, or adjustable  
Standby current: 400 nA  
Automatic battery backup power switching  
Extremely fast gating of chip enable signals (3 ns)  
Voltage monitor for power fail  
WATCHDOG  
TRANSITION DETECTOR  
(1.6sec)  
WATCHDOG  
INPUT (WDI)  
ADM8690  
POWER-FAIL  
INPUT (PFI)  
POWER-FAIL  
OUTPUT (PFO)  
1.3V  
1
2
VOLTAGE DETECTOR = 4.65V  
RESET PULSE WIDTH = 50ms  
Available in TSSOP package  
Figure 1. ADM8690  
APPLICATIONS  
Microprocessor systems  
Computers  
Controllers  
BATT ON  
ADM8691/  
ADM8695  
V
BATT  
Intelligent instruments  
Automotive systems  
V
OUT  
V
CC  
CE  
PRODUCT HIGHLIGHTS  
IN  
CE  
OUT  
The ADM8690 is available in 8-lead PDIP and SOIC packages  
and provides the following functions:  
LOW LINE  
RESET  
1
4.65V  
1. Power-on reset output during power-up, power-down,  
RESET AND  
WATCHDOG  
TIME BASE  
OSC IN  
RESET  
and brownout conditions. The  
operational with VCC as low as 1 V.  
output remains  
RESET  
GENERATOR  
RESET  
OSC SEL  
2. Battery backup switching for CMOS RAM, CMOS micro-  
processor, or other low power logic.  
WATCHDOG  
INPUT (WDI)  
WATCHDOG  
TRANSITION DETECTOR  
WATCHDOG  
TIMER  
WATCHDOG  
OUTPUT (WDO)  
3. Reset pulse if the optional watchdog timer is not toggled  
within a specified time.  
4. 1.3 V threshold detector for power-fail warning, low battery  
detection, or to monitor a power supply other than 5 V.  
POWER-FAIL  
INPUT (PFI)  
POWER-FAIL  
OUTPUT (PFO)  
1.3V  
1
VOLTAGE DETECTOR = 4.65V  
The ADM8691 and ADM8695 are available in 16-lead PDIP  
and small outline packages (including TSSOP) and provide  
three additional functions:  
Figure 2. ADM8691/ADM8695  
1. Write protection of CMOS RAM or EEPROM.  
2. Adjustable reset and watchdog timeout periods.  
3. Separate watchdog timeout, backup battery switchover, and  
low VCC status outputs.  
Rev. C  
Information furnished by Analog Devices is believed to be accurate and reliable. However, no  
responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other  
rights of third parties that may result from its use. Specifications subject to change without notice. No  
license is granted by implication or otherwise under any patent or patent rights of Analog Devices.  
Trademarks and registeredtrademarks arethe property of their respective owners.  
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.  
Tel: 781.329.4700 www.analog.com  
Fax: 781.461.3113 ©2006–2011 Analog Devices, Inc. All rights reserved.  
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
TABLE OF CONTENTS  
Features .............................................................................................. 1  
Power-Fail Warning Comparator............................................. 14  
Applications Information.............................................................. 15  
Increasing the Drive Current.................................................... 15  
Using a Rechargeable Battery for Backup ............................... 15  
Adding Hysteresis to the Power-Fail Comparator................. 15  
Monitoring the Status of the Battery ....................................... 15  
Alternate Watchdog Input Drive Circuits............................... 16  
Typical Applications....................................................................... 17  
ADM8690 Applications............................................................. 17  
ADM8691/ADM8695 Applications......................................... 17  
Applications....................................................................................... 1  
Product Highlights ........................................................................... 1  
Functional Block Diagrams............................................................. 1  
Revision History ............................................................................... 2  
General Description......................................................................... 3  
Specifications..................................................................................... 4  
Absolute Maximum Ratings............................................................ 6  
ESD Caution.................................................................................. 6  
Pin Configurations and Function Descriptions ........................... 7  
Typical Performance Characteristics ............................................. 9  
Circuit Information........................................................................ 11  
Battery Switchover Section........................................................ 11  
RESET  
Output ............................................................................ 18  
Power-Fail Detector ................................................................... 18  
RAM Write Protection............................................................... 18  
Watchdog Timer......................................................................... 18  
Outline Dimensions....................................................................... 19  
Ordering Guide .......................................................................... 22  
RESET  
Power-Fail  
Output......................................................... 11  
RESET  
Watchdog Timer  
Watchdog Output (  
............................................................ 12  
) (ADM8691/ADM8695)................. 13  
WDO  
CE  
Gating and RAM Write Protection  
(ADM8691/ADM8695)............................................................. 13  
9/06—Rev. 0 to Rev. A  
REVISION HISTORY  
Updated Format..................................................................Universal  
Changes to Absolute Maximum Ratings........................................6  
Updated Ordering Guide .............................................................. 20  
12/11—Rev. B to Rev. C  
Deleted ADM8692 and ADM8693 ............................. Throughout  
Changes to Table 4............................................................................ 7  
RESET  
Change to Power-Fail  
Output Section............................ 11  
2/97—Revision 0: Initial Version  
Changes to ADM8691/ADM8695 Applications Section .......... 17  
Updated Outline Dimensions....................................................... 19  
Changes to Ordering Guide .......................................................... 22  
6/11—Rev. A to Rev. B  
Deleted ADM8694......................................................... Throughout  
Updated Figure 11, Figure 12, and Figure 13................................ 9  
Updated Outline Dimensions....................................................... 18  
Rev. C | Page 2 of 24  
 
Data Sheet  
ADM8690/ADM8691/ADM8695  
GENERAL DESCRIPTION  
The ADM8690/ADM8691/ADM8695 supervisory circuits offer  
complete single-chip solutions for power supply monitoring and  
battery control functions in microprocessor systems. These func-  
tions include microprocessor reset, backup battery switchover,  
watchdog timer, CMOS RAM write protection, and power failure  
warning. The complete family provides a variety of configurations  
to satisfy most microprocessor system requirements.  
The ADM8690/ADM8691/ADM8695 are fabricated using an  
advanced epitaxial CMOS process that combines low power  
consumption (0.7 mW), extremely fast chip enable gating (3 ns),  
RESET  
and high reliability.  
assertion is guaranteed with VCC as  
low as 1 V. In addition, the power switching circuitry is designed  
for minimal voltage drop, thereby permitting increased output  
current drive of up to 100 mA without the need for an external  
pass transistor.  
See Table 1 for a product selection guide listing the character-  
istics of each device. To place an order, see the Ordering Guide.  
Table 1. Product Selection Guide  
Nominal Reset  
Time  
Nominal VCC  
Reset Threshold  
Nominal Watchdog  
Timeout Period  
Battery Backup  
Switching  
Base Drive,  
Ext PNP  
Chip Enable  
Signals  
Part No.  
ADM8690  
ADM8691  
ADM8695  
50 ms  
50 ms or ADJ  
200 ms or ADJ  
4.65 V  
4.65 V  
4.65 V  
1.6 sec  
100 ms, 1.6 sec, ADJ  
100 ms, 1.6 sec, ADJ  
Yes  
Yes  
Yes  
No  
Yes  
Yes  
No  
Yes  
Yes  
Rev. C | Page 3 of 24  
 
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
SPECIFICATIONS  
VCC = full operating range, VBATT = 2.8 V, TA = TMIN to TMAX, unless otherwise noted.  
Table 2.  
Parameter  
Min  
Typ  
Max  
Unit  
Test Conditions/Comments  
BATTERY BACKUP SWITCHING  
VCC Operating Voltage Range  
VBATT Operating Voltage Range  
VOUT Output Voltage  
4.75  
2.0  
VCC − 0.005  
VCC − 0.2  
5.5  
4.25  
V
V
V
V
VCC − 0.0025  
VCC − 0.125  
IOUT = 1 mA  
IOUT ≤ 100 mA  
VOUT in Battery Backup Mode  
Supply Current (Excludes IOUT  
VBATT − 0.005 VBATT − 0.002  
V
μA  
μA  
IOUT = 250 μA, VCC < VBATT − 0.2 V  
IOUT = 100 μA  
VCC = 0 V, VBATT = 2.8 V  
5.5 V > VCC > VBATT + 0.2 V  
TA = 25°C  
)
140  
0.4  
200  
1
Supply Current in Battery Backup Mode  
Battery Standby Current  
+ = Discharge, − = Charge  
Battery Switchover Threshold  
VCC − VBATT  
Battery Switchover Hysteresis  
BATT ON Output Voltage  
BATT ON Output Short-Circuit Current  
−0.1  
+0.02  
μA  
mV  
mV  
mV  
V
70  
50  
20  
Power-up  
Power-down  
0.3  
25  
ISINK = 3.2 mA  
BATT ON = VOUT = 4.5 V, sink current  
BATT ON = 0 V, source current  
55  
mA  
μA  
0.5  
4.5  
2.5  
RESET AND WATCHDOG TIMER  
Reset Voltage Threshold  
Reset Threshold Hysteresis  
Reset Timeout Delay  
4.65  
40  
4.73  
V
mV  
ADM8690 and ADM8691  
ADM8695  
Watchdog Timeout Period, Internal  
Oscillator  
35  
140  
1.0  
50  
200  
1.6  
70  
280  
2.25  
ms  
ms  
OSC SEL = high  
OSC SEL = high  
Seconds Long period  
70  
100  
4064  
1011  
140  
4097  
1025  
ms  
Cycles  
Cycles  
ns  
Short period  
Long period  
Short period  
VIL = 0.4 V, VIH = 3.5 V  
Watchdog Timeout Period, External Clock  
3840  
768  
50  
Minimum WDI Input Pulse Width  
RESET Output Voltage at VCC = 1 V  
RESET, LOW LINE Output Voltage  
4
20  
mV  
V
I
SINK = 10 μA, VCC = 1 V  
0.05  
0.4  
I
SINK = 1.6 mA, VCC = 4.25 V  
3.5  
V
V
ISOURCE = 1 μA  
SINK = 1.6 mA  
RESET, WDO Output Voltage  
0.4  
25  
I
3.5  
1
V
μA  
mA  
ISOURCE = 1 μA  
Output Short-Circuit Source Current  
Output Short-Circuit Sink Current  
WDI Input Threshold1  
Logic Low  
Logic High  
WDI Input Current  
10  
25  
0.8  
10  
V
V
μA  
μA  
3.5  
1
−1  
WDI = VOUT  
WDI = 0 V  
−10  
POWER-FAIL DETECTOR  
PFI Input Threshold  
PFI Input Current  
1.25  
−25  
1.3  
0.01  
1.35  
+25  
0.4  
V
nA  
V
VCC = 5 V  
PFO Output Voltage  
ISINK = 3.2 mA  
3.5  
1
V
ꢀA  
mA  
ISOURCE = 1 μA  
PFI = low, PFO = 0 V  
PFI = high, PFO = VOUT  
PFO Short-Circuit Source Current  
PFO Short-Circuit Sink Current  
3
25  
25  
Rev. C | Page 4 of 24  
 
Data Sheet  
ADM8690/ADM8691/ADM8695  
Parameter  
Min  
Typ  
3
Max  
Unit  
Test Conditions/Comments  
CHIP ENABLE GATING  
CEIN Threshold  
0.8  
V
VIL  
3.0  
V
μA  
V
VIH  
CEIN Pull-Up Current  
CEOUT Output Voltage  
0.4  
7
ISINK = 3.2 mA  
VOUT − 1.5  
VOUT − 0.05  
V
V
ns  
ISOURCE = 3.0 mA  
ISOURCE = 1 μA, VCC = 0 V  
CE Propagation Delay  
3
OSCILLATOR  
OSC IN Input Current  
2
5
μA  
μA  
kHz  
kHz  
OSC SEL Input Pull-Up Current  
OSC IN Frequency Range  
OSC IN Frequency with External Capacitor  
0
500  
OSC SEL = 0 V  
OSC SEL = 0 V, COSC = 47 pF  
4
1 WDI is a three-level input that is internally biased to 38% of VCC and has an input impedance of approximately 5 MΩ.  
Rev. C | Page 5 of 24  
ADM8690/ADM8691/ADM8695  
Data Sheet  
ABSOLUTE MAXIMUM RATINGS  
TA = 25°C, unless otherwise noted.  
Stresses above those listed under Absolute Maximum Ratings  
may cause permanent damage to the device. This is a stress  
rating only; functional operation of the device at these or any  
other conditions above those indicated in the operational  
section of this specification is not implied. Exposure to absolute  
maximum rating conditions for extended periods may affect  
device reliability.  
Table 3.  
Parameter  
Rating  
VCC  
−0.3 V to +6 V  
VBATT  
−0.3 V to +6 V  
All Other Inputs  
−0.3 V to VOUT + 0.5 V  
Input Current  
VCC  
VBATT  
200 mA  
50 mA  
ESD CAUTION  
GND  
20 mA  
Digital Output Current  
Power Dissipation, 8-Lead PDIP  
θJA Thermal Impedance  
Power Dissipation, 8-Lead SOIC  
θJA Thermal Impedance  
Power Dissipation, 16-Lead PDIP  
θJA Thermal Impedance  
Power Dissipation, 16-Lead TSSOP  
θJA Thermal Impedance  
Power Dissipation, 16-Lead SOIC_N  
θJA Thermal Impedance  
Power Dissipation, 16-Lead SOIC_W  
θJA Thermal Impedance  
Operating Temperature Range  
Industrial (A Version)  
Lead Temperature (Soldering, 10 sec)  
Storage Temperature Range  
20 mA  
400 mW  
120°C/W  
400 mW  
120°C/W  
600 mW  
135°C/W  
600 mW  
158°C/W  
600 mW  
110°C/W  
600 mW  
73°C/W  
−40°C to +85°C  
300°C  
−65°C to +150°C  
Rev. C | Page 6 of 24  
 
Data Sheet  
ADM8690/ADM8691/ADM8695  
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS  
V
1
2
3
4
5
6
7
8
16 RESET  
BATT  
V
RESET  
15  
OUT  
V
WDO  
14  
CC  
ADM8691/  
ADM8695  
GND  
13 CE  
12 CE  
IN  
TOP VIEW  
V
V
BATT ON  
LOW LINE  
OSC IN  
1
2
3
4
8
7
6
5
OUT  
BATT  
OUT  
(Not to Scale)  
V
ADM8690  
11 WDI  
10 PFO  
RESET  
WDI  
CC  
TOP VIEW  
GND  
PFI  
(Not to Scale)  
OSC SEL  
9
PFI  
PFO  
Figure 3. ADM8690 Pin Configuration,  
8-Lead PDIP and 8-Lead SOIC_N  
Figure 4. ADM8691/ADM8695 Pin Configuration, 16-Lead PDIP,  
16-Lead SOIC_N, 16-Lead SOIC_W, and 16-Lead TSSOP  
Table 4. Pin Function Descriptions  
Pin No.  
16-Lead  
8-Lead  
Mnemonic  
Description  
8
1
VBATT  
Backup Battery Input. VBATT or VCC is internally switched to VOUT, depending on which is at the  
highest potential.  
1
2
2
VOUT  
Output Voltage. VCC or VBATT is internally switched to VOUT, depending on which is at the highest  
potential. VOUT can supply up to 100 mA to power CMOS RAM. Connect VOUT to VCC if VOUT and VBATT  
are not used.  
Power Supply Input. 5 V nominal. VCC or VBATT is internally switched to VOUT, depending on which is  
at the highest potential.  
3
VCC  
3
N/A  
4
5
GND  
BATT ON  
Ground. This is the 0 V ground reference for all signals.  
Logic Output. BATT ON goes high when VOUT is internally switched to the VBATT input. It goes low  
when VOUT is internally switched to VCC. The output typically sinks 35 mA and can directly drive the  
base of an external PNP transistor to increase the output current above the 100 mA rating of VOUT  
Logic Output. LOW LINE goes low when VCC falls below the reset threshold. It returns high as  
soon as VCC rises above the reset threshold.  
Oscillator Logic Input. When OSC SEL is low, OSC IN can be driven by an external clock signal, or  
an external capacitor can be connected between OSC IN and GND. This sets both the reset active  
pulse timing and the watchdog timeout period (see Table 5 and Figure 17 through Figure 20).  
When OSC SEL is high or floating, the internal oscillator is enabled and the reset active time is  
fixed at 50 ms typical (ADM8691) or 200 ms typical (ADM8695). In this mode, the OSC IN pin  
selects either the fast (100 ms) or slow (1.6 sec) watchdog timeout period. In both modes, the  
timeout period immediately after a reset is 1.6 sec typical.  
.
N/A  
N/A  
6
7
LOW LINE  
OSC IN  
N/A  
8
OSC SEL  
Logic Oscillator Select Input. When OSC SEL is unconnected (floating) or driven high, the internal  
oscillator sets the reset active time and watchdog timeout period. When OSC SEL is low, the  
external oscillator input, OSC IN, is enabled (see Table 5). OSC SEL has a 5 μA internal pull-up.  
4
5
6
9
PFI  
Power-Fail Input. PFI is the noninverting input to the power-fail comparator. When PFI is less than  
1.3 V, PFO goes low. Connect PFI to GND or VOUT when not used.  
10  
11  
PFO  
WDI  
Power-Fail Output. PFO is the output of the power-fail comparator. It goes low when PFI is less  
than 1.3 V. The comparator is turned off and PFO goes low when VCC is below VBATT  
.
Watchdog Input. WDI is a three-level input. If WDI remains either high or low for longer than  
the watchdog timeout period, RESET pulses low and WDO goes low. The timer is reset with each  
transition on the WDI line. The watchdog timer can be disabled if WDI is left floating or is driven  
to midsupply.  
N/A  
12  
CEOUT  
Logic Output. CEOUT is a gated version of the CEIN signal. CEOUT tracks CEIN when VCC is above the reset  
threshold. If VCC is below the reset threshold, CEOUT is forced high. See Figure 21 and Figure 22.  
N/A  
N/A  
13  
14  
CEIN  
Logic Input. Input to the CE gating circuit. When not in use, connect this pin to GND or VOUT.  
WDO  
Logic Output. The watchdog output, WDO, goes low if WDI remains either high or low for longer  
than the watchdog timeout period. WDO is set high by the next transition at WDI. If WDI is  
unconnected or at midsupply, the watchdog timer is disabled and WDO remains high. WDO also  
goes high when LOW LINE goes low.  
Rev. C | Page 7 of 24  
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
Pin No.  
8-Lead  
16-Lead  
Mnemonic  
Description  
7
15  
RESET  
Logic Output. RESET goes low if VCC falls below the reset threshold or if the watchdog timer is not  
serviced within its timeout period. The reset threshold is typically 4.65 V. RESET remains low for  
50 ms (ADM8690/ADM8691) or 200 ms (ADM8695) after VCC returns above the threshold. RESET  
also goes low for 50 ms (ADM8690/ADM8691) or 200 ms (ADM8695) if the watchdog timer is  
enabled but not serviced within its timeout period. The RESET pulse width can be adjusted on  
the ADM8691/ADM8695, as shown in Table 5. The RESET output has an internal 3 μA pull-up and  
can either connect to an open-collector reset bus or directly drive a CMOS gate without an  
external pull-up resistor.  
N/A  
16  
RESET  
Logic Output. RESET is an active high output. It is the inverse of RESET.  
Rev. C | Page 8 of 24  
Data Sheet  
ADM8690/ADM8691/ADM8695  
TYPICAL PERFORMANCE CHARACTERISTICS  
1.315  
1.310  
1.305  
1.300  
1.295  
1.290  
1.285  
1.280  
5.00  
4.99  
4.98  
4.97  
4.96  
4.95  
4.94  
–60  
–30  
0
30  
60  
90  
120  
10  
20  
30  
40  
50  
60  
70  
80  
90  
100  
TEMPERATURE (°C)  
I
(mA)  
OUT  
Figure 8. PFI Input Threshold vs. Temperature  
Figure 5. VOUT vs. IOUT, Normal Operation  
2.800  
53  
52  
51  
V
= 5V  
CC  
2.798  
2.796  
2.794  
2.792  
2.790  
2.788  
2.786  
50  
49  
ADM8690/  
ADM8691  
20  
40  
60  
80  
100 120  
150  
250  
350  
450  
550  
650  
750  
850  
950 1050  
TEMPERATURE (°C)  
I
(µA)  
OUT  
Figure 6. VOUT vs. IOUT, Battery Backup  
Figure 9. Reset Active Time vs. Temperature  
4.69  
4.67  
V
= 5V  
CC  
A4  
3.36V  
100  
90  
4.65  
4.63  
4.61  
4.59  
4.57  
4.55  
10  
0%  
1V  
1V  
500ms  
–60  
–30  
0
30  
60  
90  
120  
TEMPERATURE (°C)  
Figure 7. Reset Output Voltage vs. Supply Voltage  
Figure 10. Reset Voltage Threshold vs. Temperature  
Rev. C | Page 9 of 24  
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
6
6
5
4
3
2
1
0
V
T
= 5V  
V
T
= 5V  
CC  
= 25°C  
CC  
= 25°C  
PFO  
5
A
A
4
3
V
PFI  
5V  
PFO  
2
1
0
1.3V  
10k  
30pF  
V
PFI  
PFO  
PFO  
PFI  
1.3V  
30pF  
PFI  
1.35  
1.25  
1.35  
1.25  
0
0.2  
0.4  
0.6  
0.8  
TIME (µs)  
1.0  
1.2  
1.4  
1.6  
1.8  
0
0.1  
0.2  
0.3  
0.4  
TIME (µs)  
0.5  
0.6  
0.7  
0.8  
Figure 11. Power-Fail Comparator Response Time, Falling  
Figure 13. Power-Fail Comparator Response Time with Pull-Up Resistor  
6
5
4
3
2
1
0
V
= 5V  
CC  
= 25°C  
T
A
V
PFI  
PFO  
1.3V  
30pF  
PFO  
PFI  
1.35  
1.25  
0
10  
20  
30  
40  
50  
60  
70  
80  
90  
TIME (µs)  
Figure 12. Power-Fail Comparator Response Time, Rising  
Rev. C | Page 10 of 24  
Data Sheet  
ADM8690/ADM8691/ADM8695  
CIRCUIT INFORMATION  
If the battery switchover section is not used, VBATT should be  
BATTERY SWITCHOVER SECTION  
connected to GND and VOUT should be connected to VCC  
.
The battery switchover circuit compares VCC to the VBATT  
input and connects VOUT to whichever is higher. Switchover  
occurs when VCC is 50 mV higher than VBATT as VCC falls, and  
when VCC is 70 mV greater than VBATT as VCC rises. This 20 mV  
hysteresis prevents repeated rapid switching if VCC falls very  
slowly or remains nearly equal to the battery voltage.  
POWER-FAIL RESET OUTPUT  
RESET  
RESET  
signal to  
is an active low output that provides a  
the microprocessor whenever VCC is at an invalid level. When  
RESET  
VCC falls below the reset threshold, the  
output is forced  
low. The nominal reset voltage threshold is 4.65 V.  
V
CC  
V2  
V2  
V
V
CC  
V1  
V1  
OUT  
V
BATT  
t1  
t1  
RESET  
GATE DRIVE  
100  
mV  
BATT ON  
(ADM8691,  
ADM8695)  
INTERNAL  
LOW LINE  
SHUTDOWN SIGNAL  
WHEN  
700  
mV  
V
> (V + 0.7V)  
BATT  
CC  
t
1
= RESET TIME  
V1 = RESET VOLTAGE THRESHOLD LOW  
V2 = RESET VOLTAGE THRESHOLD HIGH  
HYSTERESIS = V2 – V1  
Figure 14. Battery Switchover Schematic  
Figure 15. Power-Fail Reset Timing  
During normal operation, with VCC higher than VBATT, VCC  
is internally switched to VOUT through an internal PMOS tran-  
sistor switch. This switch has a typical on resistance of 0.7 Ω  
and can supply up to 100 mA at the VOUT terminal. VOUT is  
normally used to drive a RAM memory bank, requiring  
instantaneous currents of greater than 100 mA. If this is the  
case, a bypass capacitor should be connected to VOUT. The  
capacitor provides the peak current transients to the RAM.  
A capacitance value of 0.1 μF or greater can be used.  
RESET  
On power-up,  
remains low for 50 ms (200 ms for the  
ADM8695) after VCC rises above the appropriate reset thresh-  
old. This allows time for the power supply and microprocessor  
RESET  
to stabilize. On power-down, the  
output remains low  
with VCC as low as 1 V. This ensures that the microprocessor is  
held in a stable shutdown condition.  
RESET  
The  
active time is adjustable on the ADM8691/  
ADM8695 by using an external oscillator or by connecting an  
external capacitor to the OSC IN pin. See Table 5 and Figure 17  
through Figure 20.  
If the continuous output current requirements at VOUT exceed  
100 mA or if a lower VCC − VOUT voltage differential is desired,  
an external PNP pass transistor can be connected in parallel  
with the internal transistor. The BATT ON output (ADM8691/  
ADM8695) can directly drive the base of the external transistor  
(see Figure 24).  
The guaranteed minimum and maximum reset thresholds for  
the ADM8690/ADM8691/ADM8695 are 4.5 V and 4.73 V. The  
ADM8690/ADM8691/ADM8695 are, therefore, compatible with  
5 V supplies with a +10%, −5% tolerance. The reset threshold  
comparator typically has 40 mV of hysteresis. The response time  
of the reset voltage comparator is less than 1 μs. If glitches are  
present on the VCC line that could cause spurious reset pulses,  
A 7 Ω MOSFET switch connects the VBATT input to VOUT during  
battery backup. This MOSFET has very low input-to-output  
differential (dropout voltage) at the low current levels required  
for battery backup of CMOS RAM or other low power CMOS  
circuitry. The supply current in battery backup is typically 0.4 μA.  
V
CC should be decoupled close to the device.  
RESET  
In addition to  
, the ADM8691/ADM8695 provide an  
The ADM8690/ADM8691/ADM8695 operate with battery  
voltages from 2.0 V to 4.25 V. High value capacitors, either standard  
electrolytic or the farad-size, double-layer capacitors, can also be  
used for short-term memory backup. A small charging current  
of typically 10 nA (0.1 μA maximum) flows out of the VBATT  
terminal. This current is useful for maintaining rechargeable  
batteries in a fully charged condition. This extends the life of the  
backup battery by compensating for its self-discharge current.  
Also note that this current poses no problem when lithium  
batteries are used for backup because the maximum charging  
current (0.1 μA) is safe for even the smallest lithium cells.  
active high RESET output. This output is the complement of  
RESET  
and is intended for processors that require an active  
high reset signal.  
Rev. C | Page 11 of 24  
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
WATCHDOG TIMER RESET  
WDI  
The watchdog timer circuit monitors the activity of the micro-  
processor to check that it is not stalled in an indefinite loop.  
An output line on the processor is used to toggle the watchdog  
input (WDI) line. If this line is not toggled within the selected  
WDO  
RESET  
timeout period, a  
pulse is generated.  
t2  
t3  
The nominal watchdog timeout period is preset at 1.6 sec on  
the ADM8690. The ADM8691/ADM8695 can be configured for  
a fixed timeout period—short (100 ms) or long (1.6 sec)—or for  
an adjustable timeout period. Some systems are unable to service  
the watchdog timer immediately after a reset; in this case, if the  
short period is selected for the ADM8691/ADM8695, the device  
automatically selects the long timeout period directly after a  
reset is issued. The watchdog timer is restarted at the end of a  
reset, regardless of whether the reset was caused by lack of  
activity on WDI or by VCC falling below the reset threshold.  
RESET  
t1  
t1  
t1  
t1 = RESET TIME  
t2 = NORMAL (SHORT) WATCHDOG TIMEOUT PERIOD  
t3 = WATCHDOG TIMEOUT PERIOD IMMEDIATELY FOLLOWING A RESET  
Figure 16. Watchdog Timeout Period and Reset Active Time  
The internal oscillator is enabled when OSC SEL is high or  
floating. In this mode, OSC IN selects either the 1.6 sec watch-  
dog timeout period or the 100 ms watchdog timeout period.  
When OSC IN is connected high or left floating, the 1.6 sec  
timeout period is selected; when OSC IN is connected low, the  
100 ms timeout period is selected. In either case, the timeout  
period is 1.6 sec immediately after a reset. This gives the micro-  
processor time to reinitialize the system. If OSC IN is low, the  
100 ms watchdog timeout period becomes effective after the  
first transition of WDI. The software should be written such  
that the input/output port driving WDI is left in its power-up  
reset state until the initialization routines are completed and the  
microprocessor is able to toggle WDI at the minimum watchdog  
timeout period of 70 ms.  
The normal (short) timeout period becomes effective following  
RESET  
the first transition of WDI after  
has gone inactive. The  
watchdog timeout period restarts with each transition on the  
WDI pin. To ensure that the watchdog timer does not time out,  
either a high-to-low or low-to-high transition on the WDI pin  
must occur by the end of the minimum timeout period. If WDI  
remains permanently high or low, reset pulses are issued after  
each long (1.6 sec) timeout period. The watchdog monitor can  
be deactivated by allowing the watchdog input (WDI) to float  
or by connecting it to midsupply.  
On the ADM8690 the watchdog timeout period is fixed at  
1.6 sec, and the reset pulse width is fixed at 50 ms. The ADM8691/  
ADM8695 allow these times to be adjusted, as shown in Table 5.  
Figure 17, Figure 18, Figure 19, and Figure 20 show the various  
oscillator configurations that can be used to adjust the reset pulse  
width and watchdog timeout period.  
Table 5. ADM8691 and ADM8695 Reset Pulse Width and Watchdog Timeout Selections  
Watchdog Timeout Period  
Reset Active Period  
OSC SEL  
OSC IN  
Normal  
Immediately After Reset  
4096 CLKs  
1.6 sec × C/47 pF  
1.6 sec  
ADM8691  
512 CLKs  
200 ms × C/47 pF  
50 ms  
ADM8695  
Low1  
External clock input  
External capacitor  
Low  
1024 CLKs  
400 ms × C/47 pF  
100 ms  
2048 CLKs  
520 ms × C/47 pF  
200 ms  
Low1  
Floating or high  
Floating or high  
Floating or high  
1.6 sec  
1.6 sec  
50 ms  
200 ms  
1 When the OSC SEL pin is low, OSC IN can be driven by an external clock signal, or an external capacitor (C) can be connected between OSC IN and GND. The nominal  
internal oscillator frequency is 10.24 kHz. The nominal oscillator frequency with an external capacitor is fOSC (Hz) = 184,000/C (pF).  
Rev. C | Page 12 of 24  
 
 
Data Sheet  
ADM8690/ADM8691/ADM8695  
WATCHDOG OUTPUT (WDO) (ADM8691/ADM8695)  
CE GATING AND RAM WRITE PROTECTION  
(ADM8691/ADM8695)  
WDO  
The watchdog output (  
pin on the ADM8691/ADM8695)  
The ADM8691/ADM8695 include memory protection circuitry  
that ensures the integrity of data in memory by preventing write  
operations when VCC is at an invalid level. Two additional pins  
provides a status output that goes low if the watchdog timer  
times out and remains low until set high by the next transition  
WDO  
on the watchdog input.  
is also set high when VCC goes  
CE  
CE  
(
IN and OUT) can be used to control the chip enable or write  
below the reset threshold.  
CE  
inputs of CMOS RAM. When VCC is present, OUT is a buffered  
8
OSC SEL  
CE  
replica of IN, with a 3 ns propagation delay. When VCC falls  
ADM8691/  
ADM8695  
below the reset voltage threshold or VBATT, an internal gate forces  
CLOCK  
0 TO 500kHz  
CE  
CE  
OUT high, independent of  
CE CS  
, or write input of battery  
.
IN  
7
OSC IN  
CE  
OUT typically drives the  
,
backed-up CMOS RAM. This ensures the integrity of the data  
in memory by preventing write operations when VCC is at an  
invalid level. Similar protection of EEPROMs can be achieved  
Figure 17. External Clock Source  
8
OSC SEL  
CE  
using the OUT pin to drive the store or write inputs.  
ADM8691/  
ADM8695  
ADM8691/  
ADM8695  
7
OSC IN  
C
CE  
IN  
OSC  
CE  
OUT  
Figure 18. External Capacitor  
V
V
LOW = 0  
OK = 1  
CC  
CC  
8
OSC SEL  
NC  
NC  
Figure 21. Chip Enable Gating  
ADM8691/  
ADM8695  
7
V2  
V2  
OSC IN  
V
V1  
V1  
CC  
Figure 19. Internal Oscillator (1.6 Second Watchdog)  
t1  
t1  
RESET  
8
OSC SEL  
NC  
ADM8691/  
ADM8695  
LOW LINE  
7
OSC IN  
Figure 20. Internal Oscillator (100 ms Watchdog)  
CE  
IN  
CE  
OUT  
t
1
= RESET TIME  
V1 = RESET VOLTAGE THRESHOLD LOW  
V2 = RESET VOLTAGE THRESHOLD HIGH  
HYSTERESIS = V2 – V1  
Figure 22. Chip Enable Timing  
Rev. C | Page 13 of 24  
 
 
 
 
 
 
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
PFO  
is normally used to interrupt the microprocessor so  
POWER-FAIL WARNING COMPARATOR  
that data can be stored in RAM and the shutdown procedure  
executed before power is lost.  
An additional comparator is provided for early warning of  
failure in the microprocessor power supply. The power-fail  
input (PFI) is compared to an internal 1.3 V reference. The  
INPUT  
PFO  
power-fail output (  
less than 1.3 V.  
) goes low when the voltage at PFI is  
POWER  
POWER-  
FAIL  
OUTPUT  
1.3V  
PFO  
R1  
R2  
POWER- PFI  
FAIL  
INPUT  
Typically, PFI is driven by an external voltage divider that senses  
either the unregulated dc input to the system 5 V regulator or  
the regulated 5 V output. The voltage divider ratio can be chosen  
such that the voltage at PFI falls below 1.3 V several milliseconds  
before the 5 V power supply falls below the reset threshold.  
Figure 23. Power-Fail Comparator  
Table 6. Input and Output Status in Battery Backup Mode  
Signal  
Status  
VOUT  
VOUT is connected to VBATT via an internal PMOS switch.  
RESET  
RESET  
LOW LINE  
BATT ON  
WDI  
Logic low.  
Logic high. The open circuit output voltage is equal to VOUT  
Logic low.  
.
Logic high. The open circuit voltage is equal to VOUT  
WDI is ignored. It is internally disconnected from its internal pull-up resistor and does not source or sink current as long as  
its input voltage is between GND and VOUT. The input voltage does not affect supply current.  
.
WDO  
PFI  
PFO  
CEIN  
Logic high. The open circuit voltage is equal to VOUT.  
The power-fail comparator is turned off and has no effect on the power-fail output.  
Logic low.  
CEIN is ignored. It is internally disconnected from its internal pull-up resistor and does not source or sink current as long as  
its input voltage is between GND and VOUT. The input voltage does not affect supply current.  
CEOUT  
Logic high. The open circuit voltage is equal to VOUT  
OSC IN is ignored.  
OSC SEL is ignored.  
.
OSC IN  
OSC SEL  
Rev. C | Page 14 of 24  
 
Data Sheet  
ADM8690/ADM8691/ADM8695  
APPLICATIONS INFORMATION  
7V TO 15V  
INPUT  
POWER  
5V  
INCREASING THE DRIVE CURRENT  
7805  
If the continuous output current requirements at VOUT exceed  
100 mA, or if a lower VCC − VOUT voltage differential is desired,  
an external PNP pass transistor can be connected in parallel  
with the internal transistor. The BATT ON output (ADM8691/  
ADM8695) can directly drive the base of the external transistor.  
V
R4  
CC  
R1  
R2  
1.3V  
PFO  
TO  
PFI  
MICROPROCESSOR  
NMI  
R3  
PNP TRANSISTOR  
5V INPUT  
POWER  
R1 R1  
R2 R3  
0.1µF  
0.1µF  
5V  
1+  
= 1.3V  
+
V
(
)
H
L
V
V
OUT  
BATT  
ON  
CC  
R1  
R1 (5V – 1.3V)  
V
= 1.3V 1+  
(
)
PFO  
R2 R3 (1.3V (R3 + R4))  
V
BATT  
BATTERY  
ADM8691/  
ADM8695  
ASSUMING R4 < < R3 THEN  
HYSTERESIS V – V = 5V (R1)  
0V  
0V  
H
L
V
V
H
R2  
L
V
IN  
Figure 26. Adding Hysteresis to the Power-Fail Comparator  
Figure 24. Increasing the Drive Current  
MONITORING THE STATUS OF THE BATTERY  
USING A RECHARGEABLE BATTERY FOR BACKUP  
The power-fail comparator can be used to monitor the status  
of the backup battery instead of the power supply, if desired  
(see Figure 27). The PFI input samples the battery voltage and  
If a capacitor or a rechargeable battery is used for backup, the  
charging resistor should be connected to VOUT to eliminate the  
discharge path that would exist during power-down if the  
resistor were connected to VCC.  
PFO  
generates an active low  
signal when the battery voltage  
V
– V  
drops below a selected threshold. It may be necessary to apply  
a test load to determine the loaded battery voltage. This is done  
OUT  
BATT  
I =  
R
5V INPUT  
POWER  
0.1µF  
CE  
CE  
under processor control using OUT. Because OUT is forced  
high during the battery backup mode, the test load is not applied  
to the battery while it is in use, even if the microprocessor is not  
powered.  
R
0.1µF  
V
V
OUT  
CC  
V
BATT  
RECHARGEABLE  
BATTERY  
5V INPUT  
POWER  
Figure 25. Rechargeable Battery  
V
ADDING HYSTERESIS TO THE POWER-FAIL  
COMPARATOR  
V
BATT  
CC  
PFO  
LOW BATTERY  
SIGNAL TO  
MICROPROCESSOR  
I/O PIN  
BATTERY  
R1  
R2  
10M  
10MΩ  
PFI  
For increased noise immunity, hysteresis can be added to  
the power-fail comparator. Because the comparator circuit is  
noninverting, hysteresis can be added simply by connecting a  
20kΩ  
OPTIONAL  
TEST LOAD  
CE  
IN  
FROM  
MICROPROCESSOR  
I/O PIN APPLIES  
TEST LOAD  
CE  
OUT  
PFO  
PFO  
resistor between the  
Figure 26. When  
output and the PFI input, as shown in  
is low, Resistor R3 sinks current from the  
TO BATTERY  
Figure 27. Monitoring the Battery Status  
PFO  
summing junction at the PFI pin. When  
is high, the series  
combination of R3 and R4 sources current into the PFI summing  
junction. This results in differing trip levels for the comparator.  
Rev. C | Page 15 of 24  
 
 
 
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
For the ADM8691/ADM8695, the watchdog period can be  
ALTERNATE WATCHDOG INPUT DRIVE CIRCUITS  
extended under program control using the circuit shown in  
Figure 29. When the control input is high, the OSC SEL pin is  
low and the watchdog timeout is set by the external capacitor.  
A 0.01 μF capacitor sets a watchdog timeout delay of 100 sec.  
When the control input is low, the OSC SEL pin is driven high,  
selecting the internal oscillator. The 100 ms or the 1.6 sec  
period is chosen, depending on which diode is used, as shown  
in Figure 29. With D1 inserted, the internal timeout is set to  
100 ms; with D2 inserted, the timeout is set to 1.6 sec.  
The watchdog feature can be enabled and disabled under  
program control by driving WDI with a three-state buffer (see  
Figure 28). When three-stated, the WDI input floats, thereby  
disabling the watchdog timer.  
WATCHDOG  
WDI  
STROBE  
ADM8690/  
ADM8691/  
ADM8695  
CONTROL  
INPUT  
Figure 28. Enabling and Disabling the Watchdog Input  
CONTROL  
INPUT  
OSC SEL  
1
This circuit is not entirely foolproof, and it is possible for a  
software fault to erroneously three-state the buffer, preventing  
the ADM8690/ADM8691/ADM8695 from detecting that the  
microprocessor is no longer operating correctly. In most cases,  
a better method is to extend the watchdog period rather than  
disable the watchdog.  
ADM8691/  
ADM8695  
D2  
D1  
OSC IN  
1
LOW = INTERNAL TIMEOUT  
HIGH = EXTERNAL TIMEOUT  
Figure 29. Extending the Watchdog Period  
Rev. C | Page 16 of 24  
 
 
 
Data Sheet  
ADM8690/ADM8691/ADM8695  
TYPICAL APPLICATIONS  
Figure 31 shows a similar application, but in this case the PFI  
input monitors the unregulated input to the 7805 voltage regu-  
lator. This circuit provides an earlier warning of an impending  
power failure. It is useful with processors that operate at low  
speeds or where there are a significant number of housekeeping  
tasks to be completed before the power is lost.  
ADM8690 APPLICATIONS  
Figure 30 shows the ADM8690 in a typical power monitoring,  
battery backup application. VOUT powers the CMOS RAM.  
Under normal operating conditions with VCC present, VOUT  
is internally connected to VCC. If a power failure occurs, VCC  
decays and VOUT is switched to VBATT, thereby maintaining  
INPUT  
POWER  
V > 8V  
5V  
RESET  
power for the CMOS RAM. A  
pulse is also generated  
7805  
0.1µF  
0.1µF  
RESET  
when VCC falls below 4.65 V for the ADM8690.  
low for 50 ms after VCC returns to 5 V.  
remains  
R1  
R2  
V
POWER  
CC  
CMOS RAM  
POWER  
V
PFI  
OUT  
5V  
MICROPROCESSOR  
SYSTEM  
ADM8690  
R1  
POWER  
V
CC  
RESET  
RESET  
CMOS RAM  
POWER  
V
V
BATT  
PFI  
OUT  
+
PFO  
WDI  
NMI  
BATTERY  
0.1µF  
R2  
I/O LINE  
GND  
MICROPROCESSOR  
SYSTEM  
ADM8690  
RESET  
RESET  
Figure 31. ADM8690 Typical Application, Circuit B  
V
BATT  
+
PFO  
WDI  
NMI  
BATTERY  
ADM8691/ADM8695 APPLICATIONS  
I/O LINE  
GND  
Figure 32 shows a typical connection for the ADM8691/ADM8695.  
CMOS RAM is powered from VOUT. When 5 V power is present,  
Figure 30. ADM8690 Typical Application, Circuit A  
this voltage is routed to VOUT. If VCC fails, VBATT is routed to VOUT  
.
The watchdog timer input (WDI) monitors an input/output  
line from the microprocessor system. This line must be toggled  
once every 1.6 sec to verify correct software execution. Failure  
to toggle the line indicates that the microprocessor system is  
not correctly executing its program and may be tied up in an  
endless loop. If this happens, a reset pulse is generated to  
initialize the microprocessor.  
VOUT can supply up to 100 mA from VCC, but if more current is  
required, an external PNP transistor can be added. When VCC is  
higher than VBATT, the BATT ON output goes low, providing up  
to 35 mA of base drive for the external transistor. A 0.1 μF capac-  
itor is connected to VOUT to supply the transient currents for  
CMOS RAM. When VCC is lower than VBATT, an internal 20 Ω  
MOSFET connects the backup battery to VOUT  
.
If the watchdog timer is not needed, the WDI input should be  
left floating.  
INPUT POWER  
5V  
0.1µF  
0.1µF  
The power-fail input, PFI, monitors the input power supply via  
a resistive divider network. The voltage on the PFI input is  
compared with a precision 1.3 V internal reference. If the input  
V
BATT  
ON  
V
CC  
OUT  
CMOS  
RAM  
3V  
BATTERY  
CE  
V
OUT  
BATT  
ADDRESS  
DECODE  
PFO  
voltage drops below 1.3 V, a power-fail output (  
) signal is  
CE  
IN  
R1  
R2  
ADM8691/  
ADM8695  
generated. This signal warns of an impending power failure and  
can be used to interrupt the processor so that the system can be  
shut down in an orderly fashion. The resistors in the sensing  
network are ratioed to give the desired power-fail threshold  
voltage (VT).  
PFI  
A0 TO A15  
I/O LINE  
GND  
WDI  
PFO  
NC  
OSC IN  
NMI  
OSC SEL  
RESET  
RESET  
0.1µF  
MICROPROCESSOR  
SYSTEM  
LOW LINE WDO  
RESET  
VT = (1.3 R1/R2) + 1.3 V  
R1/R2 = (VT/1.3) − 1  
SYSTEM STATUS  
INDICATORS  
Figure 32. ADM8691/ADM8695 Typical Application  
Rev. C | Page 17 of 24  
 
 
 
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
RESET OUTPUT  
RAM WRITE PROTECTION  
CE  
The ADM8691/ADM8695 OUT line drives the chip select  
The internal voltage detector monitors VCC and generates a  
RESET  
CE  
CE  
output to hold the microprocessor reset line low when  
inputs of the CMOS RAM. OUT follows IN as long as VCC  
is above the 4.65 V reset threshold.  
RESET  
VCC is below 4.65 V. An internal timer holds  
low for  
50 ms (200 ms for the ADM8695) after VCC rises above 4.65 V.  
RESET  
power drops out and recovers with each power line cycle.  
CE  
If VCC falls below the reset threshold, OUT goes high, independent  
This prevents repeated toggling of  
, even if the 5 V  
CE  
of the logic level at IN. This prevents the microprocessor from  
writing erroneous data into RAM during power-up, power-down,  
brownouts, and momentary power interruptions.  
The crystal oscillator normally used to generate the clock for  
microprocessors can take several milliseconds to stabilize.  
Because most microprocessors need several clock cycles to  
WATCHDOG TIMER  
The microprocessor drives the watchdog input (WDI) with an  
input/output line. When OSC IN and OSC SEL are unconnected,  
the microprocessor must toggle the WDI pin once every 1.6 sec  
to verify proper software execution. If a hardware or software fail-  
ure occurs such that WDI is not toggled, the ADM8691 issues a  
RESET  
reset,  
must be held low until the microprocessor clock  
RESET  
oscillator has started. The power-up  
pulse lasts 50 ms  
(200 ms for the ADM8695) to allow for this oscillator start-up  
time. If a different reset pulse width is required, a capacitor  
should be connected to OSC IN, or an external clock can be  
used (see Table 5 and Figure 17 through Figure 20). The manual  
reset switch and the 0.1 μF capacitor connected to the reset line  
can be omitted if a manual reset is not needed. An inverted,  
active high RESET output is also available on the ADM8691/  
ADM8695.  
RESET  
50 ms (200 ms for the ADM8695)  
typically restarts the microprocessor power-up routine. A new  
RESET  
pulse after 1.6 sec. This  
pulse is issued every 1.6 sec until WDI is again strobed.  
If a different watchdog timeout period is required, a capacitor  
should be connected to OSC IN or an external clock can be  
used (see Table 5 and Figure 17 through Figure 20).  
POWER-FAIL DETECTOR  
WDO  
The watchdog output (  
not serviced within its timeout period. After  
) goes low if the watchdog timer is  
WDO  
The 5 V VCC power line is monitored via a resistive potential  
divider connected to the power-fail input (PFI). When the voltage  
goes low, it  
remains low until a transition occurs at WDI. The watchdog  
timer feature can be disabled by leaving WDI unconnected.  
PFO  
at PFI falls below 1.3 V, the power-fail output (  
) drives the  
processors NMI input low. For example, if a power-fail threshold  
of 4.8 V is set with Resistor R1 and Resistor R2 and VCC falls from  
4.8 V to 4.65 V, the microprocessor has time to save data into RAM.  
An earlier power-fail warning can be generated if the unregulated  
dc input to the 5 V regulator is available for monitoring. This  
allows more time for microprocessor housekeeping tasks to be  
completed before power is lost.  
RESET  
The  
output has an internal 3 μA pull-up and can either  
connect to an open-collector reset bus or directly drive a CMOS  
gate without an external pull-up resistor.  
Rev. C | Page 18 of 24  
 
 
Data Sheet  
ADM8690/ADM8691/ADM8695  
OUTLINE DIMENSIONS  
0.400 (10.16)  
0.365 (9.27)  
0.355 (9.02)  
8
1
5
4
0.280 (7.11)  
0.250 (6.35)  
0.240 (6.10)  
0.325 (8.26)  
0.310 (7.87)  
0.300 (7.62)  
0.100 (2.54)  
BSC  
0.060 (1.52)  
MAX  
0.195 (4.95)  
0.130 (3.30)  
0.115 (2.92)  
0.210 (5.33)  
MAX  
0.015  
(0.38)  
MIN  
0.150 (3.81)  
0.130 (3.30)  
0.115 (2.92)  
0.015 (0.38)  
GAUGE  
0.014 (0.36)  
0.010 (0.25)  
0.008 (0.20)  
PLANE  
SEATING  
PLANE  
0.022 (0.56)  
0.018 (0.46)  
0.014 (0.36)  
0.430 (10.92)  
MAX  
0.005 (0.13)  
MIN  
0.070 (1.78)  
0.060 (1.52)  
0.045 (1.14)  
COMPLIANT TO JEDEC STANDARDS MS-001  
CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
CORNER LEADS MAY BE CONFIGURED AS WHOLE OR HALF LEADS.  
Figure 33. 8-Lead Plastic Dual In-Line Package [PDIP]  
Narrow Body  
(N-8)  
Dimensions shown in inches and (millimeters)  
5.00 (0.1968)  
4.80 (0.1890)  
8
1
5
4
6.20 (0.2441)  
5.80 (0.2284)  
4.00 (0.1574)  
3.80 (0.1497)  
0.50 (0.0196)  
0.25 (0.0099)  
1.27 (0.0500)  
BSC  
45°  
1.75 (0.0688)  
1.35 (0.0532)  
0.25 (0.0098)  
0.10 (0.0040)  
8°  
0°  
0.51 (0.0201)  
0.31 (0.0122)  
COPLANARITY  
0.10  
1.27 (0.0500)  
0.40 (0.0157)  
0.25 (0.0098)  
0.17 (0.0067)  
SEATING  
PLANE  
COMPLIANT TO JEDEC STANDARDS MS-012-AA  
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 34. 8-Lead Standard Small Outline Package [SOIC_N]  
Narrow Body  
(R-8)  
Dimensions shown in millimeters and (inches)  
Rev. C | Page 19 of 24  
 
ADM8690/ADM8691/ADM8695  
Data Sheet  
0.800 (20.32)  
0.790 (20.07)  
0.780 (19.81)  
16  
1
9
8
0.280 (7.11)  
0.250 (6.35)  
0.240 (6.10)  
0.325 (8.26)  
0.310 (7.87)  
0.300 (7.62)  
0.100 (2.54)  
BSC  
0.060 (1.52)  
MAX  
0.195 (4.95)  
0.130 (3.30)  
0.115 (2.92)  
0.210 (5.33)  
MAX  
0.015  
(0.38)  
MIN  
0.150 (3.81)  
0.130 (3.30)  
0.115 (2.92)  
0.015 (0.38)  
GAUGE  
0.014 (0.36)  
0.010 (0.25)  
0.008 (0.20)  
PLANE  
SEATING  
PLANE  
0.022 (0.56)  
0.018 (0.46)  
0.014 (0.36)  
0.430 (10.92)  
MAX  
0.005 (0.13)  
MIN  
0.070 (1.78)  
0.060 (1.52)  
0.045 (1.14)  
COMPLIANT TO JEDEC STANDARDS MS-001-AB  
CONTROLLING DIMENSIONS ARE IN INCHES; MILLIMETER DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF INCH EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
CORNER LEADS MAY BE CONFIGURED AS WHOLE OR HALF LEADS.  
Figure 35. 16-Lead Plastic Dual In-Line Package [PDIP]  
Narrow Body  
(N-16)  
Dimensions shown in inches and (millimeters)  
10.50 (0.4134)  
10.10 (0.3976)  
16  
1
9
8
7.60 (0.2992)  
7.40 (0.2913)  
10.65 (0.4193)  
10.00 (0.3937)  
0.75 (0.0295)  
0.25 (0  
.0098)  
1.27 (0.0500)  
BSC  
45°  
2.65 (0.1043)  
2.35 (0.0925)  
0.30 (0.0118)  
0.10 (0.0039)  
8°  
0°  
COPLANARITY  
0.10  
SEATING  
PLANE  
0.51 (0.0201)  
0.31 (0.0122)  
1.27 (0.0500)  
0.40 (0.0157)  
0.33 (0.0130)  
0.20 (0.0079)  
COMPLIANT TO JEDEC STANDARDS MS-013-AA  
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 36. 16-Lead Standard Small Outline Package [SOIC_W]  
Wide Body  
(RW-16)  
Dimensions shown in millimeters and (inches)  
Rev. C | Page 20 of 24  
Data Sheet  
ADM8690/ADM8691/ADM8695  
10.00 (0.3937)  
9.80 (0.3858)  
9
8
16  
1
6.20 (0.2441)  
5.80 (0.2283)  
4.00 (0.1575)  
3.80 (0.1496)  
1.27 (0.0500)  
BSC  
0.50 (0.0197)  
45°  
0.25 (0.0098)  
1.75 (0.0689)  
1.35 (0.0531)  
0.25 (0.0098)  
0.10 (0.0039)  
8°  
0°  
COPLANARITY  
0.10  
SEATING  
PLANE  
1.27 (0.0500)  
0.40 (0.0157)  
0.51 (0.0201)  
0.31 (0.0122)  
0.25 (0.0098)  
0.17 (0.0067)  
COMPLIANT TO JEDEC STANDARDS MS-012-AC  
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS  
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR  
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN.  
Figure 37. 16-Lead Standard Small Outline Package [SOIC_N]  
Narrow Body  
(R-16)  
Dimensions shown in millimeters and (inches)  
5.10  
5.00  
4.90  
16  
9
8
4.50  
4.40  
4.30  
6.40  
BSC  
1
PIN 1  
1.20  
MAX  
0.15  
0.05  
0.20  
0.09  
0.75  
0.60  
0.45  
8°  
0°  
0.30  
0.19  
0.65  
BSC  
SEATING  
PLANE  
COPLANARITY  
0.10  
COMPLIANT TO JEDEC STANDARDS MO-153-AB  
Figure 38. 16-Lead Thin Shrink Small Outline Package [TSSOP]  
(RU-16)  
Dimensions shown in millimeters  
Rev. C | Page 21 of 24  
ADM8690/ADM8691/ADM8695  
Data Sheet  
ORDERING GUIDE  
Model1  
Temperature Range  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
Package Description  
Package Option  
ADM8690AN  
ADM8690ANZ  
ADM8690ARN  
ADM8690ARN-REEL  
ADM8690ARNZ  
ADM8691ANZ  
8-Lead Plastic Dual In-Line Package [PDIP]  
8-Lead Plastic Dual In-Line Package [PDIP]  
8-Lead Standard Small Outline Package [SOIC_N]  
8-Lead Standard Small Outline Package [SOIC_N]  
8-Lead Standard Small Outline Package [SOIC_N]  
16-Lead Plastic Dual In-Line Package [PDIP]  
16-Lead Standard Small Outline Package [SOIC_N]  
16-Lead Standard Small Outline Package [SOIC_N]  
16-Lead Standard Small Outline Package [SOIC_N]  
16-Lead Standard Small Outline Package [SOIC_W]  
16-Lead Standard Small Outline Package [SOIC_W]  
16-Lead Standard Small Outline Package [SOIC_W]  
16-Lead Thin Shrink Small Outline Package [TSSOP]  
16-Lead Thin Shrink Small Outline Package [TSSOP]  
16-Lead Thin Shrink Small Outline Package [TSSOP]  
16-Lead Standard Small Outline Package [SOIC_W]  
16-Lead Standard Small Outline Package [SOIC_W]  
16-Lead Standard Small Outline Package [SOIC_W]  
N-8  
N-8  
R-8  
R-8  
R-8  
N-16  
R-16  
R-16  
ADM8691ARN  
ADM8691ARN-REEL  
ADM8691ARNZ  
ADM8691ARW  
ADM8691ARW-REEL  
ADM8691ARWZ  
ADM8691ARU  
ADM8691ARU-REEL  
ADM8691ARUZ  
ADM8695ARW  
ADM8695ARW-REEL  
ADM8695ARWZ  
R-16  
RW-16  
RW-16  
RW-16  
RU-16  
RU-16  
RU-16  
RW-16  
RW-16  
RW-16  
1 Z = RoHS Compliant Part.  
Rev. C | Page 22 of 24  
 
 
Data Sheet  
NOTES  
ADM8690/ADM8691/ADM8695  
Rev. C | Page 23 of 24  
ADM8690/ADM8691/ADM8695  
NOTES  
Data Sheet  
©2006–2011 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D00093-0-12/11(C)  
Rev. C | Page 24 of 24  

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