ADP3650JRZ-RL [ROCHESTER]

AND GATE BASED MOSFET DRIVER, PDSO8, ROHS COMPLIANT, MS-012AA, SOIC-8;
ADP3650JRZ-RL
型号: ADP3650JRZ-RL
厂家: Rochester Electronics    Rochester Electronics
描述:

AND GATE BASED MOSFET DRIVER, PDSO8, ROHS COMPLIANT, MS-012AA, SOIC-8

驱动 光电二极管 接口集成电路 驱动器
文件: 总13页 (文件大小:1131K)
中文:  中文翻译
下载:  下载PDF数据表文档文件
Dual, Bootstrapped, 12 V MOSFET  
Driver with Output Disable  
ADP3650  
FEATURES  
GENERAL DESCRIPTION  
All-in-one synchronous buck driver  
Bootstrapped high-side drive  
One PWM signal generates both drives  
Anti-crossconduction protection circuitry  
OD for disabling the driver outputs  
The ADP3650 is a dual, high voltage MOSFET driver optimized  
for driving two N-channel MOSFETs, the two switches in a  
nonisolated synchronous buck power converter. Each driver is  
capable of driving a 3000 pF load with a 45 ns propagation delay  
and a 25 ns transition time. One of the drivers can be boot-  
strapped and is designed to handle the high voltage slew rate  
associated with floating high-side gate drivers. The ADP3650  
includes overlapping drive protection to prevent shoot-through  
current in the external MOSFETs.  
APPLICATIONS  
Telecom and datacom networking  
Industrial and medical systems  
Point of load conversion: memory, DSP, FPGA, ASIC  
The  
pin shuts off both the high-side and the low-side  
OD  
MOSFETs to prevent rapid output capacitor discharge during  
system shutdown.  
The ADP3650 is specified over the temperature range of −40°C  
to +85°C and is available in 8-lead SOIC_N and 8-lead LFCSP_VD  
packages.  
FUNCTIONAL BLOCK DIAGRAM  
12V  
D1  
VCC  
4
BST  
ADP3650  
1
8
C
BST2  
C
LATCH  
R1  
BST1  
2
R
G
IN  
DRVH  
R2  
S
Q
Q1  
DELAY  
R
BST  
TO  
INDUCTOR  
SW  
7
CMP  
VCC  
6
CMP  
DRVL  
PGND  
1V  
CONTROL  
LOGIC  
5
6
Q2  
DELAY  
3
OD  
Figure 1.  
Rev. A  
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 ©2008–2010 Analog Devices, Inc. All rights reserved.  
 
 
ADP3650  
TABLE OF CONTENTS  
Features .............................................................................................. 1  
Low-Side Driver ............................................................................9  
High-Side Driver...........................................................................9  
Overlap Protection Circuit...........................................................9  
Applications Information.............................................................. 10  
Supply Capacitor Selection ....................................................... 10  
Bootstrap Circuit........................................................................ 10  
MOSFET Selection..................................................................... 10  
High-Side (Control) MOSFETs................................................ 10  
Low-Side (Synchronous) MOSFETs ........................................ 11  
PCB Layout Considerations...................................................... 11  
Outline Dimensions....................................................................... 12  
Ordering Guide .......................................................................... 12  
Applications....................................................................................... 1  
General Description......................................................................... 1  
Functional Block Diagram .............................................................. 1  
Revision History ............................................................................... 2  
Specifications..................................................................................... 3  
Timing Characteristics ................................................................ 4  
Absolute Maximum Ratings............................................................ 5  
Thermal Resistance ...................................................................... 5  
ESD Caution.................................................................................. 5  
Pin Configurations and Function Descriptions ........................... 6  
Typical Performance Characteristics ............................................. 7  
Theory of Operation ........................................................................ 9  
REVISION HISTORY  
7/10—Rev. 0 to Rev. A  
Changes to General Description Section ...................................... 1  
Changes to Table 1............................................................................ 3  
Changes to Operating Ambient Temperature Range Parameter,  
Table 2 ................................................................................................ 5  
Changes to Figure 8 and Figure 9................................................... 7  
Changes to Ordering Guide .......................................................... 12  
10/08—Revision 0: Initial Version  
Rev. A | Page 2 of 12  
 
ADP3650  
SPECIFICATIONS  
VCC = 12 V, BST = 4 V to 26 V, TA = −40°C to +85°C, unless otherwise noted.1  
Table 1.  
Parameter  
Symbol  
Test Conditions/Comments  
Min  
Typ  
Max  
Unit  
DIGITAL INPUTS (IN, OD)  
Input Voltage High  
Input Voltage Low  
Input Current  
2.0  
V
V
μA  
mV  
0.8  
+1  
350  
−1  
40  
Hysteresis  
250  
2.5  
HIGH-SIDE DRIVER  
Output Resistance, Sourcing Current  
BST − SW = 12 V; TA = 25°C  
BST − SW = 12 V; TA = −40°C to +85°C  
BST − SW = 12 V; TA = 25°C  
BST − SW = 12 V; TA = −40°C to +85°C  
BST − SW = 0 V  
BST − SW = 12 V, CLOAD = 3 nF, see Figure 3  
BST − SW = 12 V, CLOAD = 3 nF, see Figure 3  
BST − SW = 12 V, CLOAD = 3 nF,  
25°C ≤ TA ≤ 85°C, see Figure 3  
BST − SW = 12 V, CLOAD = 3 nF, see Figure 3  
See Figure 2  
3.3  
3.9  
1.8  
2.6  
Ω
Ω
Ω
Ω
kΩ  
ns  
ns  
ns  
Output Resistance, Sinking Current  
1.4  
10  
25  
20  
45  
Output Resistance, Unbiased  
Transition Times  
trDRVH  
tfDRVH  
tpdhDRVH  
40  
30  
70  
Propagation Delay Times  
32  
tpdlDRVH  
25  
20  
35  
35  
ns  
ns  
tpdl  
OD  
See Figure 2  
SW to PGND  
40  
10  
55  
ns  
t
pdh  
OD  
SW Pull-Down Resistance  
LOW-SIDE DRIVER  
kΩ  
Output Resistance, Sourcing Current  
TA = 25°C  
TA = −40°C to +85°C  
TA = 25°C  
TA = −40°C to +85°C  
VCC = PGND  
CLOAD = 3 nF, see Figure 3  
CLOAD = 3 nF, see Figure 3  
CLOAD = 3 nF, see Figure 3  
CLOAD = 3 nF, see Figure 3  
See Figure 2  
3.3  
3.9  
1.8  
2.6  
Ω
Ω
Ω
Ω
kΩ  
ns  
ns  
ns  
ns  
ns  
2.4  
Output Resistance, Sinking Current  
1.4  
10  
20  
16  
12  
30  
20  
Output Resistance, Unbiased  
Transition Times  
trDRVL  
tfDRVL  
tpdhDRVL  
tpdlDRVL  
35  
30  
35  
45  
35  
Propagation Delay Times  
t
pdl  
OD  
See Figure 2  
110  
190  
ns  
tpdh  
OD  
Timeout Delay  
SW = 5 V  
SW = PGND  
110  
95  
190  
150  
ns  
ns  
SUPPLY  
Supply Voltage Range  
Supply Current  
UVLO Voltage  
Hysteresis  
VCC  
ISYS  
4.15  
1.5  
13.2  
5
3.0  
V
mA  
V
BST = 12 V, IN = 0 V  
VCC rising  
2
350  
mV  
1 All limits at temperature extremes are guaranteed via correlation using standard statistical quality control (SQC) methods.  
Rev. A | Page 3 of 12  
 
ADP3650  
TIMING CHARACTERISTICS  
Timing is referenced to the 90% and 10% points, unless otherwise noted.  
OD  
tpdlOD  
tpdhOD  
90%  
DRVH  
OR  
DRVL  
10%  
Figure 2. Output Disable Timing Diagram  
IN  
tpdlDRVL  
tfDRVL  
tpdlDRVH  
trDRVL  
DRVL  
tfDRVH  
tpdhDRVH trDRVH  
DRVH  
TO  
SW  
V
V
TH  
TH  
tpdhDRVL  
SW  
1V  
Figure 3. Timing Diagram  
Rev. A | Page 4 of 12  
 
 
 
ADP3650  
ABSOLUTE MAXIMUM RATINGS  
All voltages are referenced to PGND, 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 2.  
Parameter  
Rating  
VCC  
−0.3 V to +15 V  
BST  
DC  
−0.3 V to VCC + 15 V  
−0.3 V to +35 V  
−0.3 V to +15 V  
<200 ns  
BST to SW  
SW  
THERMAL RESISTANCE  
θJA is specified for the worst-case conditions, that is, a device  
soldered in a circuit board for surface-mount packages.  
DC  
−5 V to +15 V  
−10 V to +25 V  
<200 ns  
DRVH  
DC  
<200 ns  
DRVL  
DC  
Table 3. Thermal Resistance  
Package Type  
θJA  
Unit  
SW − 0.3 V to BST + 0.3 V  
SW − 2 V to BST + 0.3 V  
8-Lead SOIC_N (R-8)  
2-Layer Board  
4-Layer Board  
8-Lead LFCSP_VD1 (CP-8-2)  
123  
90  
°C/W  
°C/W  
−0.3 V to VCC + 0.3 V  
−2 V to VCC + 0.3 V  
−0.3 V to +6.5 V  
<200 ns  
IN, OD  
4-Layer Board  
50  
°C/W  
Operating Ambient Temperature Range −40°C to +85°C  
1 For LFCSP_VD, θJA is measured per JEDEC STD with exposed pad soldered to PCB.  
Junction Temperature Range  
Storage Temperature Range  
Lead Temperature  
0°C to 150°C  
−65°C to +150°C  
ESD CAUTION  
Soldering (10 sec)  
Vapor Phase (60 sec)  
Infrared (15 sec)  
300°C  
215°C  
260°C  
Rev. A | Page 5 of 12  
 
ADP3650  
PIN CONFIGURATIONS AND FUNCTION DESCRIPTIONS  
PIN 1  
INDICATOR  
BST  
IN  
1
2
3
4
DRVH  
SW  
8
7
6
5
ADP3650  
TOP VIEW  
(Not to Scale)  
1
2
3
4
8
7
6
5
DRVH  
SW  
BST  
IN  
PGND  
DRVL  
OD  
ADP3650  
VCC  
OD  
VCC  
PGND  
DRVL  
TOP VIEW  
(Not to Scale)  
NOTES  
1. IT IS RECOMMENDED THAT THE  
EXPOSED PAD AND THE PGND PIN  
BE CONNECTED ON THE PCB.  
Figure 5. 8-Lead LFCSP_VD Pin Configuration  
Figure 4. 8-Lead SOIC_N Pin Configuration  
Table 4. Pin Function Descriptions  
Pin No. Mnemonic Description  
1
BST  
Upper MOSFET Floating Bootstrap Supply. A capacitor connected between the BST and SW pins holds this  
bootstrapped voltage for the high-side MOSFET while it is switching.  
2
IN  
Logic Level PWM Input. This pin has primary control of the drive outputs. In normal operation, pulling this pin  
low turns on the low-side driver; pulling it high turns on the high-side driver.  
3
4
5
6
OD  
Output Disable. When low, this pin disables normal operation, forcing DRVH and DRVL low.  
Input Supply. This pin should be bypassed to PGND with an ~1 μF ceramic capacitor.  
Synchronous Rectifier Drive. Output drive for the lower (synchronous rectifier) MOSFET.  
Power Ground. This pin should be closely connected to the source of the lower MOSFET. This pin is not internally  
connected to the exposed pad on the LFCSP. It is recommended that this pin and the exposed pad be  
connected on the PCB.  
VCC  
DRVL  
PGND  
7
SW  
Switch Node Connection. This pin is connected to the buck switching node, close to the upper MOSFET source.  
It is the floating return for the upper MOSFET drive signal. It is also used to monitor the switched voltage to  
prevent the lower MOSFET from turning on until the voltage is below ~1 V.  
8
DRVH  
Buck Drive. Output drive for the upper (buck) MOSFET.  
EP  
Exposed pad  
For the LFCSP, the exposed pad and the PGND pin should be connected on the PCB. For more information  
about exposed pad packages, see the AN-772 Application Note at www.analog.com.  
Rev. A | Page 6 of 12  
 
ADP3650  
TYPICAL PERFORMANCE CHARACTERISTICS  
19.0  
18.5  
18.0  
17.5  
17.0  
16.5  
16.0  
15.5  
15.0  
14.5  
14.0  
IN  
DRVH  
DRVL  
1
2
DRVL  
DRVH  
3
CH1 5V  
CH2 5V  
M40ns  
20.2%  
A CH1  
2.4V  
–40 –30 –20 –10  
0
10 20 30 40 50 60 70 80  
T
CH3 10V  
JUNCTION TEMPERATURE (°C)  
Figure 6. DRVH Rise and DRVL Fall Times,  
LOAD = 6 nF for DRVL, CLOAD = 2 nF for DRVH  
Figure 9. DRVH and DRVL Fall Times vs. Temperature  
C
40  
35  
30  
25  
20  
15  
10  
5
T
= 25°C  
A
VCC = 12V  
DRVH  
IN  
1
DRVL  
DRVL  
2
DRVH  
3
CH1 5V  
CH2 5V  
M40ns  
20.2%  
A CH1  
2.4V  
2.0  
2.5  
3.0  
3.5  
4.0  
4.5  
5.0  
T
CH3 10V  
LOAD CAPACITANCE (nF)  
Figure 7. DRVH Fall and DRVL Rise Times,  
Figure 10. DRVH and DRVL Rise Times vs. Load Capacitance  
CLOAD = 6 nF for DRVL, CLOAD = 2 nF for DRVH  
28  
26  
24  
22  
20  
18  
16  
14  
35  
VCC = 12V  
DRVL  
DRVH  
T
= 25°C  
A
30  
25  
20  
15  
10  
5
DRVH  
DRVL  
–40 –30 –20 –10  
0
10 20 30 40 50 60 70 80  
2.0  
2.5  
3.0  
3.5  
4.0  
4.5  
5.0  
JUNCTION TEMPERATURE (°C)  
LOAD CAPACITANCE (nF)  
Figure 11. DRVH and DRVL Fall Times vs. Load Capacitance  
Figure 8. DRVH and DRVL Rise Times vs. Temperature  
Rev. A | Page 7 of 12  
 
ADP3650  
60  
12  
11  
10  
9
T
= 25°C  
A
T
= 25°C  
A
VCC = 12V  
C
C
= 3nF  
LOAD  
= 3nF  
LOAD  
45  
30  
15  
0
8
7
6
5
4
3
2
1
0
0
200  
400  
600  
800  
1000  
1200  
1400  
0
1
2
3
4
5
6
7
8
9
10 11 12  
FREQUENCY (kHz)  
V
(V)  
CC  
Figure 12. Supply Current vs. Frequency  
Figure 14. DRVL Output Voltage vs. Supply Voltage  
13  
VCC = 12V  
= 3nF  
C
LOAD  
= 250kHz  
f
IN  
12  
11  
10  
9
0
25  
50  
75  
100  
125  
JUNCTION TEMPERATURE (°C)  
Figure 13. Supply Current vs. Temperature  
Rev. A | Page 8 of 12  
ADP3650  
THEORY OF OPERATION  
The ADP3650 is optimized for driving two N-channel  
MOSFETs in a synchronous buck converter topology. A single  
PWM input (IN) signal is all that is required to properly drive  
the high-side and the low-side MOSFETs. Each driver is capable  
of driving a 3 nF load at speeds up to 500 kHz. A functional  
block diagram of the ADP3650 is shown in Figure 1.  
OVERLAP PROTECTION CIRCUIT  
The overlap protection circuit prevents both of the main power  
switches, Q1 and Q2, from being on at the same time. This is  
done to prevent shoot-through currents from flowing through  
both power switches and the associated losses that can occur  
during their on/off transitions. The overlap protection circuit  
accomplishes this by adaptively controlling the delay from the  
Q1 turn-off to the Q2 turn-on and by internally setting the  
delay from the Q2 turn-off to the Q1 turn-on.  
LOW-SIDE DRIVER  
The low-side driver is designed to drive a ground referenced  
N-channel MOSFET. The bias supply to the low-side driver is  
internally connected to the VCC supply and PGND.  
To prevent the overlap of the gate drives during the Q1 turn-off  
and the Q2 turn-on, the overlap circuit monitors the voltage at  
the SW pin. When the PWM input signal goes low, Q1 begins  
to turn off (after propagation delay). Before Q2 can turn on, the  
overlap protection circuit makes sure that SW has first gone  
high and then waits for the voltage at the SW pin to fall from  
When the driver is enabled, the driver output is 180° out of  
phase with the PWM input. When the ADP3650 is disabled,  
the low-side gate is held low.  
HIGH-SIDE DRIVER  
V
IN to 1 V. When the voltage on the SW pin falls to 1 V, Q2  
The high-side driver is designed to drive a floating N-channel  
MOSFET. The bias voltage for the high-side driver is developed  
by an external bootstrap supply circuit that is connected  
between the BST and SW pins.  
begins to turn on. If the SW pin has not gone high first, the Q2  
turn-on is delayed by a fixed 150 ns. By waiting for the voltage  
on the SW pin to reach 1 V or for the fixed delay time, the  
overlap protection circuit ensures that Q1 is off before Q2 turns  
on, regardless of variations in temperature, supply voltage, input  
pulse width, gate charge, and drive current. If SW does not go  
below 1 V after 190 ns, DRVL turns on. This can occur if the  
current flowing in the output inductor is negative and flows  
through the high-side MOSFET body diode.  
The bootstrap circuit comprises Diode D1 and Bootstrap  
Capacitor CBST1. CBST2 and RBST are included to reduce the high-  
side gate drive voltage and to limit the switch node slew rate.  
When the ADP3650 starts up, the SW pin is at ground, so the  
bootstrap capacitor charges up to VCC through D1. When the  
PWM input goes high, the high-side driver begins to turn on  
the high-side MOSFET, Q1, by pulling charge out of CBST1 and  
CBST2. As Q1 turns on, the SW pin rises up to VIN and forces the  
BST pin to VIN + VC (BST). This holds Q1 on because enough gate-  
to-source voltage is provided. To complete the cycle, Q1 is  
switched off by pulling the gate down to the voltage at the SW  
pin. When the low-side MOSFET, Q2, turns on, the SW pin is  
pulled to ground. This allows the bootstrap capacitor to charge  
up to VCC again.  
The output of the high-side driver is in phase with the PWM  
input. When the driver is disabled, the high-side gate is held low.  
Rev. A | Page 9 of 12  
 
ADP3650  
APPLICATIONS INFORMATION  
A small signal diode can be used for the bootstrap diode due  
to the ample gate drive voltage supplied by VCC. The bootstrap  
diode must have a minimum 15 V rating to withstand the  
maximum supply voltage. The average forward current can  
be estimated by  
SUPPLY CAPACITOR SELECTION  
For the supply input (VCC) of the ADP3650, a local bypass  
capacitor is recommended to reduce noise and to supply some  
of the peak currents that are drawn. Use a 4.7 μF, low ESR  
capacitor. Multilayer ceramic chip (MLCC) capacitors provide  
the best combination of low ESR and small size. Keep the  
ceramic capacitor as close as possible to the ADP3650.  
IF(AVG) = QGATE × fMAX  
(3)  
where fMAX is the maximum switching frequency of the  
controller.  
BOOTSTRAP CIRCUIT  
The bootstrap circuit uses a charge storage capacitor (CBST  
)
The peak surge current rating should be calculated by  
and a diode, as shown in Figure 1. These components can be  
selected after the high-side MOSFET is chosen. The bootstrap  
capacitor must have a voltage rating that can handle twice the  
maximum supply voltage. A minimum 50 V rating is recom-  
mended. The capacitor values are determined by  
QGATE  
VCC VD  
RBST  
IF(PEAK )  
=
(4)  
MOSFET SELECTION  
When interfacing the ADP3650 to external MOSFETs, the  
designer should consider ways to make a robust design that  
minimizes stresses on both the driver and the MOSFETs. These  
stresses include exceeding the short time duration voltage  
ratings on the driver pins as well as on the external MOSFET.  
CBST1 + CBST2 = 10×  
(1)  
VGATE  
VGATE  
CBST1 + CBST2 VCC VD  
where:  
CBST1  
=
(2)  
It is also highly recommended that the bootstrap circuit be used  
to improve the interaction of the driver with the characteristics  
of the MOSFETs (see the Bootstrap Circuit section). If a simple  
bootstrap arrangement is used, make sure to include a proper  
snubber network on the SW node.  
QGATE is the total gate charge of the high-side MOSFET at VGATE  
VGATE is the desired gate drive voltage (usually in the range of  
5 V to 10 V, 7 V being typical).  
.
VD is the voltage drop across D1.  
HIGH-SIDE (CONTROL) MOSFETS  
Rearranging Equation 1 and Equation 2 to solve for CBST1 yields  
A high-side, high speed MOSFET is usually selected to  
minimize switching losses. This typically implies a low gate  
resistance and low input capacitance/charge device. Yet, a  
significant source lead inductance can also exist that depends  
mainly on the MOSFET package; it is best to contact the  
MOSFET vendor for this information.  
QGATE  
CBST1 = 10×  
VCC VD  
C
BST2 can then be found by rearranging Equation 1.  
QGATE  
VGATE  
CBST2 =10×  
CBST1  
The ADP3650 DRVH output impedance and the input resistance  
of the MOSFETs determine the rate of charge delivery to the  
internal capacitance of the gate. This determines the speed at  
which the MOSFETs turn on and off. However, because of  
potentially large currents flowing in the MOSFETs at the on and  
off times (this current is usually larger at turn-off due to ramping  
up of the output current in the output inductor), the source lead  
inductance generates a significant voltage when the high-side  
MOSFETs switch off. This creates a significant drain-source  
voltage spike across the internal die of the MOSFETs and can  
lead to a catastrophic avalanche. The mechanisms involved in  
this avalanche condition are referenced in literature from the  
MOSFET suppliers.  
For example, an NTD60N02 has a total gate charge of about  
12 nC at VGATE = 7 V. Using VCC = 12 V and VD = 1 V, then  
CBST1 = 12 nF and CBST2 = 6.8 nF. Good quality ceramic capacitors  
should be used.  
R
BST is used to limit slew rate and minimize ringing at the switch  
node. It also provides peak current limiting through D1. An  
BST value of 1.5 Ω to 2.2 Ω is a good choice. The resistor needs  
R
to handle at least 250 mW due to the peak currents that flow  
through it.  
Rev. A | Page 10 of 12  
 
 
ADP3650  
The MOSFET vendor should provide a safe operating rating for  
maximum voltage slew rate at a given drain current. This allows  
the designer to derate for the FET turn-off condition described  
in this section. When this specification is obtained, determine  
the maximum current expected in the MOSFET by  
However, during the low-side turn-off to high-side turn-on,  
the SW pin does not contain information for determining  
the proper switching time, so the state of the DRVL pin is  
monitored to go below one-sixth of VCC; then, a delay is added.  
Due to the Miller capacitance and internal delays of the low-  
side MOSFET gate, ensure that the Miller-to-input capacitance  
ratio is low enough, and that the low-side MOSFET internal  
delays are not so large as to allow accidental turn-on of the  
low-side MOSFET when the high-side MOSFET turns on.  
DMAX  
f MAX ×LOUT  
I MAX = IDC (per phase)+  
(
VCC VOUT  
)
×
(5)  
where:  
DMAX is determined by the voltage controller being used with  
the driver. This current is divided roughly equally between  
MOSFETs if more than one is used (assume a worst-case  
mismatch of 30% for design margin).  
PCB LAYOUT CONSIDERATIONS  
Use the following general guidelines when designing printed  
circuit boards. Figure 15 shows an example of the typical land  
patterns based on these guidelines.  
LOUT is the output inductor value.  
Trace out the high current paths and use short, wide  
(>20 mil) traces to make these connections.  
Minimize trace inductance between the DRVH and DRVL  
outputs and the MOSFET gates.  
Connect the PGND pin of the ADP3650 as close as  
possible to the source of the lower MOSFET.  
Locate the VCC bypass capacitor as close as possible to  
the VCC and PGND pins.  
When producing the design, there is no exact method for  
calculating the dV/dt due to the parasitic effects in the external  
MOSFETs as well as in the PCB. However, it can be measured to  
determine whether it is safe. If it appears that the dV/dt is too  
fast, an optional gate resistor can be added between DRVH and  
the high-side MOSFETs. This resistor slows down the dV/dt,  
but it increases the switching losses in the high-side MOSFETs.  
The ADP3650 is optimally designed with an internal drive  
impedance that works with most MOSFETs to switch them  
efficiently, yet minimizes dV/dt. However, some high speed  
MOSFETs may require this external gate resistor depending on  
the currents being switched in the MOSFET.  
When possible, use vias to other layers to maximize  
thermal conduction away from the IC.  
C
BST1  
LOW-SIDE (SYNCHRONOUS) MOSFETS  
The low-side MOSFETs are usually selected to have a low on  
resistance to minimize conduction losses. This usually implies a  
large input gate capacitance and gate charge. The first concern is  
to make sure that the power delivery from the ADP3650 DRVL  
does not exceed the thermal rating of the driver.  
R
C
BST  
BST2  
D1  
The next concern for the low-side MOSFETs is to prevent  
them from being inadvertently switched on when the high-side  
MOSFET turns on. This occurs due to the drain-gate capacitance  
(Miller capacitance, also specified as Crss) of the MOSFET. When  
the drain of the low-side MOSFET is switched to VCC by the  
high-side MOSFET turning on (at a dV/dt rate), the internal  
gate of the low-side MOSFET is pulled up by an amount roughly  
equal to VCC × (Crss/Ciss). It is important to make sure that this  
does not put the MOSFET into conduction.  
C
VCC  
Another consideration is the nonoverlap circuitry of the  
ADP3650 that attempts to minimize the nonoverlap period.  
During the state of the high-side MOSFET turning off to the  
low-side MOSFET turning on, the SW pin is monitored (as well  
as the conditions of SW prior to switching) to adequately  
prevent overlap.  
Figure 15. External Component Placement Example  
Rev. A | Page 11 of 12  
 
 
ADP3650  
OUTLINE DIMENSIONS  
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 16. 8-Lead Standard Small Outline Package [SOIC_N]  
Narrow Body  
(R-8)  
Dimensions shown in millimeters and (inches)  
3.25  
3.00 SQ  
2.75  
0.60 MAX  
0.50  
BSC  
0.60 MAX  
5
8
2.95  
2.75 SQ  
2.55  
1.60  
1.45  
1.30  
EXPOSED  
PAD  
TOP  
VIEW  
PIN 1  
INDICATOR  
(BOTTOM VIEW)  
4
1
PIN 1  
INDICATOR  
0.50  
0.40  
0.30  
1.89  
1.74  
1.59  
12° MAX  
0.70 MAX  
0.65TYP  
0.90 MAX  
0.85 NOM  
0.05 MAX  
0.01 NOM  
FOR PROPER CONNECTION OF  
THE EXPOSED PAD, REFER TO  
THE PIN CONFIGURATION AND  
FUNCTION DESCRIPTIONS  
0.30  
0.23  
0.18  
SEATING  
PLANE  
0.20 REF  
SECTION OF THIS DATA SHEET.  
Figure 17. 8-Lead Lead Frame Chip Scale Package [LFCSP_VD]  
3 mm x 3 mm Body, Very Thin, Dual Lead  
(CP-8-2)  
Dimensions shown in millimeters  
ORDERING GUIDE  
Package Ordering  
Model1  
Temperature Range  
−40°C to +85°C  
−40°C to +85°C  
−40°C to +85°C  
Package Description  
Option  
Quantity  
Branding  
ADP3650JRZ  
ADP3650JRZ-RL  
ADP3650JCPZ-RL  
8-Lead Standard Small Outline Package (SOIC_N)  
8-Lead Standard Small Outline Package (SOIC_N)  
8-Lead Lead Frame Chip Scale Package (LFCSP_VD)  
R-8  
98  
R-8  
CP-8-2  
2,500  
5,000  
L91  
1 Z = RoHS Compliant Part.  
©2008–2010 Analog Devices, Inc. All rights reserved. Trademarks and  
registered trademarks are the property of their respective owners.  
D07826-0-7/10(A)  
Rev. A | Page 12 of 12  
 
 

相关型号:

ADP3654

High Speed, Dual, 4 A MOSFET Driver
ADI

ADP3654ARDZ-R7

High Speed, Dual, 4 A MOSFET Driver
ADI

ADP3654ARDZ-RL

High Speed, Dual, 4 A MOSFET Driver
ADI

ADP3654ARHZ

High Speed, Dual, 4 A MOSFET Driver
ADI

ADP3654ARHZ-R7

High Speed, Dual, 4 A MOSFET Driver
ADI

ADP3654ARHZ-RL

High Speed, Dual, 4 A MOSFET Driver
ADI

ADP3682

GPS Ceramic Diplexer
DILABS

ADP3801

High Frequency Switch Mode Dual Li-Ion Battery Chargers
ADI

ADP3801AR

High Frequency Switch Mode Dual Li-Ion Battery Chargers
ADI

ADP3801AR-REEL

BATTERY CHARGE CONTROLLER, 250 kHz SWITCHING FREQ-MAX, PDSO16, SOIC-16
ROCHESTER

ADP3801_15

High Frequency Switch Mode Dual Li-Ion Battery Chargers
ADI

ADP3802

High Frequency Switch Mode Dual Li-Ion Battery Chargers
ADI