DS1210S/T&R [MAXIM]
Power Supply Support Circuit, Fixed, 3 Channel, CMOS, PDSO16, 0.300 INCH, SOIC-16;
| 型号： | DS1210S/T&R |
| 厂家： | 
MAXIM INTEGRATED PRODUCTS |
| 描述： | Power Supply Support Circuit, Fixed, 3 Channel, CMOS, PDSO16, 0.300 INCH, SOIC-16 光电二极管 |
| 文件： | 总8页 (文件大小：334K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
19-6294; Rev 6/12
DS1210
Nonvolatile Controller Chip
FEATURES
. Converts CMOS RAMs into Nonvolatile
Memories
PIN ASSIGNMENT
VCCO
1
8
VCCI
VBAT2
CEO
CE
VBAT1
TOL
2
3
4
7
6
5
. Unconditionally Write Protects when VCC is
Out-of-Tolerance
. Automatically Switches to Battery when
Power-Fail Occurs
GND
DS1210 8-pin PDIP (300 mils)
. Space-Saving 8-Pin PDIP or 16-Pin SO
Packages
1
2
3
4
5
6
7
8
NC
VCCO
NC
NC
16
15
14
13
12
11
10
9
. Consumes <100nA of Battery Current
. Tests Battery Condition on Power up
. Provides for Redundant Batteries
. Optional 5% or 10% Power-Fail Detection
. Low Forward Voltage Drop on the VCC
Switch
VCCI
NC
VBAT1
NC
VBAT2
NC
TOL
CEO
NC
NC
GND
CE
. Optional Industrial (N) Temperature Range of
-40°C to +85°C
DS1210S 16-pin SO (300 mils)
PIN DESCRIPTION
VCCO
VBAT1
TOL
- RAM Supply
- + Battery 1
- Power Supply Tolerance
- Ground
GND
CE
- Chip Enable Input
CEO
VBAT2
VCCI
NC
- Chip Enable Output
- + Battery 2
- + Supply
- No Connect
DESCRIPTION
The DS1210 Nonvolatile Controller Chip is a CMOS circuit which solves the application problem of
converting CMOS RAM into nonvolatile memory. Incoming power is monitored for an out-of-tolerance
condition. When such a condition is detected, chip enable is inhibited to accomplish write protection and
the battery is switched on to supply the RAM with uninterrupted power. Special circuitry uses a low-
leakage CMOS process which affords precise voltage detection at extremely low battery consumption.
The 8-pin DIP package keeps PC board real estate requirements to a minimum. By combining the
DS1210 Nonvolatile Controller Chip with a CMOS memory and batteries, nonvolatile RAM operation
can be achieved.
1 of 8
DS1210
OPERATION
The DS1210 nonvolatile controller performs five circuit functions required to battery back up a RAM.
First, a switch is provided to direct power from the battery or the incoming supply (VCCI) depending on
which is greater. This switch has a voltage drop of less than 0.3V.
The second function which the nonvolatile controller provides is power-fail detection. The DS1210
constantly monitors the incoming supply. When the supply goes out of tolerance, a precision comparator
detects power-fail and inhibits chip enable (CEO ).
The third function of write protection is accomplished by holding the CEO output signal to within 0.2
volts of the VCCI or battery supply. If CE input is low at the time power-fail detection occurs, the CEO
output is kept in its present state until CE is returned high. The delay of write protection until the current
memory cycle is completed prevents the corruption of data. Power-fail detection occurs in the range of
4.75 volts to 4.5 volts with the tolerance (TOL) pin grounded. If TOL in connected to VCCO, then power-
fail detection occurs in the range of 4.5 volts to 4.25 volts. During nominal supply conditions CEO will
follow CE with a maximum propagation delay of 20ns.
The fourth function the DS1210 performs is a battery status warning so that potential data loss is avoided.
Each time that the circuit is powered up the battery voltage is checked with a precision comparator. If the
battery voltage is less than 2.0 volts, the second memory cycle is inhibited. Battery status can, therefore,
be determined by performing a read cycle after power-up to any location in memory, verifying that
memory location content. A subsequent write cycle can then be executed to the same memory location
altering the data. If the next read cycle fails to verify the written data, then the batteries are less than 2.0V
and data is in danger of being corrupted.
The fifth function of the nonvolatile controller provides for battery redundancy. In many applications,
data integrity is paramount. In these applications it is often desirable to use two batteries to ensure
reliability. The DS1210 controller provides an internal isolation switch which allows the connection of
two batteries. During battery backup operation the battery with the highest voltage is selected for use. If
one battery should fail, the other will take over the load. The switch to a redundant battery is transparent
to circuit operation and to the user. A battery status warning will occur when the battery in use falls below
2.0 volts. A grounded VBAT2 pin will not activate a battery-fail warning. In applications where battery
redundancy is not required, a single battery should be connected to the BAT1 pin, and the BAT2 battery
pin must be grounded. The nonvolatile controller contains circuitry to turn off the battery backup. This is
to maintain the battery(s) at its highest capacity until the equipment is powered up and valid data is
written to the SRAM. While in the freshness seal mode the CEO and VCCO will be forced to VOL. When
the batteries are first attached to one or both of the VBAT pins, VCCO will not provide battery back-up until
VCCI exceeds VCCTP, as set by the TOL pin, and then falls below VBAT
.
Figure 1 shows a typical application incorporating the DS1210 in a microprocessor-based system. Section
A shows the connections necessary to write protect the RAM when VCC is less than 4.75 volts and to back
up the supply with batteries. Section B shows the use of the DS1210 to halt the processor when VCC is
less than 4.75 volts and to delay its restart on power-up to prevent spurious writes.
2 of 8
DS1210
SECTION A - BATTERY BACKUP Figure 1
BATTERY BACKUP CURRENT DRAIN EXAMPLE
CONSUMPTION
DS1210 IBAT
RAM ICC02
Total Drain
100 nA
10 µA
10.1 µA
SECTION B - PROCESSOR RESET
3 of 8
DS1210
ABSOLUTE MAXIMUM RATINGS
Voltage Range on Any Pin Relative to Ground
Operating Temperature Range
-0.3V to +7.0V
0°C to +70°C, -40°C to +85°C for N parts
Storage Temperature Range
Soldering Temperature (reflow, SO)
Lead Temperature (soldering, 10s)
-55°C to +125°C
+260°C
+300°C
This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the
operation sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods of
time may affect reliability.
PACKAGE THERMAL CHARACTERISTICS (Note 1)
PDIP
Junction-to-Ambient Thermal Resistance (θJA).…………………...…………………………...….110°C/W
Junction-to-Case Thermal Resistance (θJC)…………………………………………………………40°C/W
SO
Junction-to-Ambient Thermal Resistance (θJA).…………………………………………………….70°C/W
Junction-to-Case Thermal Resistance (θJC)…………………………………………………………23°C/W
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a four-layer board for the SO.
Note 1:
For detailed information on package thermal considerations, refer to www.maxim-ic.com/thermal-tutorial.
RECOMMENDED OPERATING CONDITIONS
(Note 10)
UNITS NOTES
PARAMETER
SYMBOL
VCCI
MIN
4.75
4.5
TYP
5.0
5.0
MAX
5.5
5.5
VCC+0.3
+0.8
4.0
TOL = GND Supply Voltage
TOL = VCCO Supply Voltage
Logic 1 Input
V
V
V
V
V
2
2
2
2
2, 3
VCCI
VIH
2.2
Logic 0 Input
Battery Input
VIL
VBAT1
-0.3
2.0
,
VBAT2
DC ELECTRICAL CHARACTERISTICS
(Note 10; VCCI = 4.75 to 5.5V, TOL = GND)
(VCCI = 4.5 to 5.5V, TOL = VCCO
)
PARAMETER
Supply Current
Supply Voltage
Supply Current
Input Leakage
Output Leakage
SYMBOL
ICCI
MIN
TYP
MAX
UNITS NOTES
5
mA
V
mA
µA
µA
mA
4
2
5
VCCO
ICCO1
IIL
ILO
IOH
VCC-0.2
80
+1.0
+1.0
-1.0
-1.0
-1.0
6
6
CEO Output @ 2.4V
IOL
4.0
mA
CEO Output @ 0.4V
VCC Trip Point (TOL=GND)
VCCTP
VCCTP
VOHL
4.50
4.25
VBAT-0.2
4.62
4.37
4.74
4.49
V
V
V
2
2
8
VCC Trip Point (TOL=VCCO
)
CEO Output
VBAT1 or VBAT2
Battery Current
Battery Backup Current
@ VCCO = VBAT – 0.3V
IBAT
100
50
nA
µA
3, 4
7, 8
ICCO2
4 of 8
DS1210
CAPACITANCE
PARAMETER
Input Capacitance
Output Capacitance
(TA = +25°C)
UNITS NOTES
SYMBOL
CIN
MIN
TYP
MAX
5
7
pF
pF
COUT
AC ELECTRICAL CHARACTERISTICS
(Note 10; VCCI = 4.75V to 5.5V, TOL = GND)
(VCCI = 4.5V to 5.5V, TOL = VCCO
)
PARAMETER
SYMBOL
MIN
TYP
MAX
UNITS NOTES
tPD
5
10
20
ns
6
CE Propagation Delay
CE High to Power-Fail
tPF
0
ns
AC ELECTRICAL CHARACTERISTICS
(Note 10; VCCI = 4.75V, TOL = GND)
(VCCI < 4.5, TOL = VCCO
)
Recovery at Power Up
tREC
tF
tFB
tR
2
300
10
0
80
125
ms
µs
µs
µs
VCC Slew Rate Power-Down
VCC Slew Rate Power-Down
VCC Slew Rate Power-Up
tCE
1.5
µs
9
CE Pulse Width
NOTES:
2. All voltages are referenced to ground.
3. Only one battery input is required. Unused battery inputs must be grounded.
4. Measured with VCCO and CEO open.
5. ICC01 is the maximum average load which the DS1210 can supply to the memories.
6. Measured with a load as shown in Figure 2.
7. ICC02 is the maximum average load current which the DS1210 can supply to the memories in the battery backup mode.
8. tCE max must be met to ensure data integrity on power loss.
9. CEO can only sustain leakage current in the battery backup mode.
10. All AC and DC electrical characteristics are valid for the full temperature range. For commercial products, this range is 0
to +70°C. For industrial products (N), this range is -40°C to +85°C.
11. DS1210 is recognized by Underwriters Laboratories (UL) under file E99151.
5 of 8
DS1210
TIMING DIAGRAM: POWER-UP
TIMING DIAGRAM: POWER-DOWN
OUTPUT LOAD Figure 2
6 of 8
DS1210
ORDERING INFORMATION
PIN-
PACKAGE
8 PDIP
PART
TEMP RANGE
DS1210+
0°C to +70°C
DS1210N+
DS1210S+
DS1210SN+
-40°C to +85°C 8 PDIP
0°C to +70°C 16 SO
-40°C to +85°C 16 SO
+Denotes a lead(Pb)-free/RoHS-compliant package.
PACKAGE INFORMATION
For the latest package outline information and land patterns (footprints), go to www.maxim-ic.com/packages.
Note that a “+”, “#”, or “-” in the package code indicates RoHS status only. Package drawings may show a
different suffix character, but the drawing pertains to the package regardless of RoHS status.
PACKAGE TYPE
8 PDIP
PACKAGE CODE
P8+4
OUTLINE NO.
21-0043
LAND PATTERN NO.
16 SO
W16+2
21-0042
90-0107
7 of 8
DS1210
REVISION HISTORY
REVISION
PAGES
CHANGED
DESCRIPTION
DATE
Added lead temperature and soldering temperature information to
the Absolute Maximum Ratings section; changed “Pin 3” to “TOL”
in multiple places; added the Package Thermal Characteristics
section; added the Ordering Information and Package Information
sections
6/12
1, 2, 4, 5, 8
8 of 8
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim
reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, Inc. 160 Rio Robles, San Jose, CA 95134 USA 1-408-601-1000
© 2012 Maxim Integrated Products
Maxim is a registered trademark of Maxim Integrated Products, Inc.
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