INTERSIL ISL6596

ISL6596
®
Data Sheet
November 2, 2005
FN9240.0
Synchronous Rectified MOSFET Driver
Features
The ISL6596 is a high frequency, MOSFET driver optimized
to drive two N-Channel power MOSFETs in a synchronous
buck converter topology. This driver combined with Intersil’s
Multi-Phase Buck PWM controllers forms a complete singlestage core-voltage regulator solution with high efficiency
performance at high switching frequency for advanced
microprocessors.
• Drives Two N-Channel MOSFETs
The IC is biased by a single low voltage supply (5V),
minimizing driver switching losses in high MOSFET gate
capacitance and high switching frequency applications.
Each driver is capable of driving a 3nF load with less than
10ns rise/fall time. Bootstrapping of the upper gate driver is
implemented via an internal low forward drop diode,
reducing implementation cost, complexity, and allowing the
use of higher performance, cost effective N-Channel
MOSFETs. Adaptive shoot-through protection is integrated
to prevent both MOSFETs from conducting simultaneously.
The ISL6596 features 4A typical sink current for the lower
gate driver, enhancing the lower MOSFET gate hold-down
capability during PHASE node rising edge, preventing power
loss caused by the self turn-on of the lower MOSFET due to
the high dV/dt of the switching node.
The ISL6596 also features an input that recognizes a highimpedance state, working together with Intersil multi-phase
3.3V or 5V PWM controllers to prevent negative transients
on the controlled output voltage when operation is
suspended. This feature eliminates the need for the schottky
diode that may be utilized in a power system to protect the
load from negative output voltage damage.
• Adaptive Shoot-Through Protection
• 0.4Ω On-Resistance and 4A Sink Current Capability
• Supports High Switching Frequency
- Fast Output Rise and Fall Time
- Low Tri-State Hold-Off Time (20ns)
• Support 3.3V and 5V PWM Input
• Low Quiescent Supply Current
• Power-On Reset
• Expandable Bottom Copper Pad for Heat Spreading
• Dual Flat No-Lead (DFN) Package
- Compliant to JEDEC PUB95 MO-220 QFN-Quad Flat
No Leads-Product Outline
- Near Chip-Scale Package Footprint; Improves PCB
Efficiency and Thinner in Profile
• Pb-Free Plus Anneal Available (RoHS Compliant)
Ordering Information
PART
NUMBER
ISL6596CBZ
(Note)
• Core Voltage Supplies for Intel® and AMD®
Microprocessors
• High Frequency Low Profile High Efficiency DC/DC
Converters
• High Current Low Voltage DC/DC Converters
6596CBZ
ISL6596CBZ-T 6596CBZ
(Note)
ISL6596CRZ
(Note)
Applications
PART
MARKING
596Z
TEMP
RANGE
(°C)
0 to 70
PACKAGE
8 Ld SOIC
PKG.
DWG. #
M8.15
8 Ld SOIC Tape and Reel
0 to 70
10 Ld 3x3 DFN L10.3x3
ISL6596CRZ-T 596Z
(Note)
10 Ld DFN Tape and Reel
ISL6596IBZ
(Note)
-40 to 85 8 Ld SOIC
ISL6596IBZ-T
(Note)
8 Ld SOIC Tape and Reel
M8.15
• Synchronous Rectification for Isolated Power Supplies
ISL6596IRZ
(Note)
96IZ
-40 to 85 10 Ld 3x3 DFN L10.3x3
Related Literature
ISL6596IRZ-T
(Note)
96IZ
10 Ld DFN Tape and Reel
• Technical Brief TB389 “PCB Land Pattern Design and
Surface Mount Guidelines for QFN (MLFP) Packages”
• Technical Brief TB363 “Guidelines for Handling and
Processing Moisture Sensitive Surface Mount Devices
(SMDs)”
1
NOTE: Intersil Pb-free plus anneal products employ special Pb-free
material sets; molding compounds/die attach materials and 100%
matte tin plate termination finish, which are RoHS compliant and
compatible with both SnPb and Pb-free soldering operations. Intersil
Pb-free products are MSL classified at Pb-free peak reflow
temperatures that meet or exceed the Pb-free requirements of
IPC/JEDEC J STD-020.
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774 Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright © Intersil Americas Inc. 2005. All Rights Reserved
Intel® is a registered trademark of Intel Corporation. AMD® is a registered trademark of Advanced Micro Devices, Inc.
ISL6596
Pinout
ISL6596 (SOIC)
TOP VIEW
ISL6596 (DFN)
TOP VIEW
UGATE
1
8
PHASE
UGATE
1
10 PHASE
BOOT
2
7
VCTRL
BOOT
2
9
VCTRL
PWM
3
6
VCC
N/C
GND
4
5
LGATE
N/C
3
8
PWM
4
7
VCC
GND
5
6
LGATE
Block Diagram
ISL6596
VCC
BOOT
VCTRL
UGATE
7k
CONTROL
LOGIC
PWM
PHASE
SHOOTTHROUGH
PROTECTION
7k
VCC
LGATE
GND
VCTRL = CONTROLLER VCC
2
FN9240.0
November 2, 2005
ISL6596
Typical Application - Multi-Phase Converter Using ISL6596 Gate Drivers
VIN
+5V
+3.3V
+3.3V
FB
COMP
VCTRL
VCC
VSEN
PWM1
RUGPH
UGATE
PWM
ISL6596
PWM2
PGOOD
BOOT
VCC
PHASE
LGATE
PWM
CONTROLLER
(ISL69XX)
ISEN1
VID
(OPTIONAL)
GND
VIN
BOOT
VCC
FS/EN
+VCORE
+5V
ISEN2
VCTRL
UGATE
RUGPH
PWM
ISL6596
PHASE
LGATE
RUGPH IS REQUIRED FOR SPECIAL POWER SEQUENCING APPLICATIONS
(SEE APPLICATION INFORMATION SECTION ON PAGE 8)
3
FN9240.0
November 2, 2005
ISL6596
Absolute Maximum Ratings
Thermal Information
Supply Voltage (VCC, VCTRL) . . . . . . . . . . . . . . . . . . . -0.3V to 7V
Input Voltage (VEN, VPWM) . . . . . . . . . . . . . . . -0.3V to VCC + 0.3V
BOOT Voltage (VBOOT-GND). . . -0.3V to 25V (DC) or 36V (<200ns)
BOOT To PHASE Voltage (VBOOT-PHASE) . . . . . . -0.3V to 7V (DC)
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 9V (<10ns)
PHASE Voltage . . . . . . . . . . . . . . . . . . . . . GND - 0.3V to 15V (DC)
. . . . . . . . . GND -8V (<20ns Pulse Width, 10µJ) to 30V (<100ns)
UGATE Voltage . . . . . . . . . . . . . . . . VPHASE - 0.3V (DC) to VBOOT
. . . . . . . . . . . VPHASE - 5V (<20ns Pulse Width, 10µJ) to VBOOT
LGATE Voltage . . . . . . . . . . . . . . . GND - 0.3V (DC) to VCC + 0.3V
. . . . . . . . . . GND - 2.5V (<20ns Pulse Width, 5µJ) to VCC + 0.3V
Ambient Temperature Range . . . . . . . . . . . . . . . . . . .-40°C to 125°C
HBM ESD Rating . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2kV
Thermal Resistance (Notes 1, 2, & 3)
θJA (°C/W)
θJC (°C/W)
SOIC Package (Note 1) . . . . . . . . . . . . 110
N/A
DFN Package (Notes 2 & 3). . . . . . . . . 48
7
Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . 150°C
Maximum Storage Temperature Range . . . . . . . . . . . -65°C to 150°C
Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300°C
(SOIC - Lead Tips Only)
Recommended Operating Conditions
Ambient Temperature Range. . . . . . . . . . . . . . . . . . . -40°C to 100°C
Maximum Operating Junction Temperature. . . . . . . . . . . . . . 125°C
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V ±10%
CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the
device at these or any other conditions above those indicated in the operational sections of this specification is not implied.
NOTES:
1. θJA is measured with the component mounted on a high effective thermal conductivity test board in free air. See Tech Brief TB379 for details.
2. θJA is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features.
3. θJC, "case temperature" location is at the center of the package underside exposed pad. See Tech Brief TB379 for details.
Electrical Specifications
These specifications apply for Recommended Operating Conditions, unless otherwise noted.
PARAMETER
SYMBOL
TEST CONDITIONS
MIN
TYP
MAX
UNITS
µA
VCC SUPPLY CURRENT
-
190
-
POR Rising
-
3.4
4.2
POR Falling
2.2
3.0
-
-
400
-
Bias Supply Current
IVCC
PWM pin floating, VVCC = 5V
Hysteresis
mV
VCTRL INPUT
Rising Threshold
-
2.75
2.90
V
Falling Threshold
2.4
2.65
-
V
-
3.5
-
kΩ
kΩ
PWM INPUT
Sinking Impedance
RPWM_SNK
Source Impedance
RPWM_SRC
Tri-State LowerThreshold
Tri-State Upper Threshold
Tri-State Shutdown Holdoff Time
tTSSHD
-
3.5
-
VVCTRL = 3.3V (-110mV Hysteresis)
-
1.1
-
V
VVCTRL = 5V (-250mV Hysteresis)
-
1.5
-
V
VVCTRL = 3.3V (+110mV Hysteresis)
-
1.9
-
V
VVCTRL = 5V (+250mV Hysteresis)
-
3.25
-
V
tPDLU or tPDLL + Gate Falling Time
-
20
-
ns
SWITCHING TIME (See Figure 1 on Page 5)
UGATE Rise Time (Note 4)
tRU
VVCC = 5V, 3nF Load
-
8.0
-
ns
LGATE Rise Time (Note 4)
tRL
VVCC = 5V, 3nF Load
-
8.0
-
ns
UGATE Fall Time (Note 4)
tFU
VVCC = 5V, 3nF Load
-
8.0
-
ns
LGATE Fall Time (Note 4)
tFL
VVCC = 5V, 3nF Load
-
4.0
-
ns
tPDLU
VVCC = 5V, Outputs Unloaded
-
20
-
ns
LGATE Turn-Off Propagation Delay
tPDLL
VVCC = 5V, Outputs Unloaded
-
15
-
ns
UGATE Turn-On Propagation Delay
tPDHU
VVCC = 5V, Outputs Unloaded
-
19
-
ns
LGATE Turn-On Propagation Delay
tPDHL
VVCC = 5V, Outputs Unloaded
-
18
-
ns
tPTS
VVCC = 5V, Outputs Unloaded
-
30
-
ns
UGATE Turn-Off Propagation Delay
Tri-state to UG/LG Rising Propagation Delay
OUTPUT (Note 4)
Upper Drive Source Resistance
RUG_SRC
250mA Source Current
-
1.0
2.5
Ω
Upper Drive Sink Resistance
RUG_SNK
250mA Sink Current
-
1.0
2.5
Ω
Lower Drive Source Resistance
RLG_SRC
250mA Source Current
-
1.0
2.5
Ω
Lower Drive Sink Resistance
RLG_SNK
250mA Sink Current
-
0.4
1.0
Ω
NOTE:
4. Guaranteed by Characterization. Not 100% tested in production.
4
FN9240.0
November 2, 2005
ISL6596
Functional Pin Description
LGATE (Pin 5)
Note: Pin numbers refer to the SOIC package. Check
diagram for corresponding DFN pinout.
Lower gate drive output. Connect to gate of the low side
N-Channel power MOSFET. A gate resistor is never
recommended on this pin, as it interferes with the operation
shoot-through protection circuitry.
UGATE (Pin 1)
Upper gate drive output. Connect to gate of high-side
N-Channel power MOSFET. A gate resistor is never
recommended on this pin, as it interferes with the operation
shoot-through protection circuitry.
VCC (Pin 6)
Connect this pin to a +5V bias supply. Locally bypass with a
high quality ceramic capacitor to ground.
BOOT (Pin 2)
VCTRL (Pin 7)
Floating bootstrap supply pin for the upper gate drive.
Connect a bootstrap capacitor between this pin and the
PHASE pin. The bootstrap capacitor provides the charge
used to turn on the upper MOSFET. See the Bootstrap
Considerations section for guidance in choosing the
appropriate capacitor value.
This pin sets the PWM logic threshold. Connect this pin to
3.3V source for 3.3V PWM input and pull it to 5V source for
5V PWM input.
PWM (Pin 3)
The PWM signal is the control input for the driver. The PWM
signal can enter three distinct states during operation, see the
Tri-state PWM Input section for further details. Connect this pin
to the PWM output of the controller.
GND (Pin 4)
Ground pin. All signals are referenced to this node.
PHASE (Pin 8)
Connect this pin to the source of the upper MOSFET. This
pin provides the return path for the upper gate driver current.
Thermal Pad (in DFN only)
The metal pad underneath the center of the IC is a thermal
substrate. The PCB “thermal land” design for this exposed
die pad should include vias that drop down and connect to
one or more buried copper plane(s). This combination of
vias for vertical heat escape and buried planes for heat
spreading allows the DFN to achieve its full thermal
potential. This pad should be either grounded or floating,
and it should not be connected to other nodes. Refer to
TB389 for design guidelines.
Timing Diagram
50% of VCC
PWM
tPDHU
tPDLU
tTSSHD
tRU
tRU
tFU
tPTS
1V
UGATE
LGATE
tPTS
1V
tRL
tTSSHD
tPDHL
tPDLL
tFL
FIGURE 1. TIMING DIAGRAM
5
FN9240.0
November 2, 2005
ISL6596
Operation and Adaptive Shoot-Through Protection
Designed for high speed switching, the ISL6596 MOSFET
driver controls both high-side and low-side N-Channel FETs
from one externally provided PWM signal.
A rising transition on PWM initiates the turn-off of the lower
MOSFET (see Timing Diagram). After a short propagation
delay [tPDLL], the lower gate begins to fall. Typical fall times
[tFL] are provided in the Electrical Specifications. Adaptive
shoot-through circuitry monitors the LGATE voltage and turns
on the upper gate following a short delay time [tPDHU] after
the LGATE voltage drops below ~1V. The upper gate drive
then begins to rise [tRU] and the upper MOSFET turns on.
A falling transition on PWM indicates the turn-off of the upper
MOSFET and the turn-on of the lower MOSFET. A short
propagation delay [tPDLU] is encountered before the upper gate
begins to fall [tFU]. The adaptive shoot-through circuitry
monitors the UGATE-PHASE voltage and turns on the lower
MOSFET a short delay time, tPDHL, after the upper MOSFET’s
gate voltage drops below 1V. The lower gate then rises [tRL],
turning on the lower MOSFET. These methods prevent both the
lower and upper MOSFETs from conducting simultaneously
(shoot-through), while adapting the dead time to the gate
charge characteristics of the MOSFETs being used.
This driver is optimized for voltage regulators with large step
down ratio. The lower MOSFET is usually sized larger
compared to the upper MOSFET because the lower
MOSFET conducts for a longer time during a switching
period. The lower gate driver is therefore sized much larger
to meet this application requirement. The 0.4Ω on-resistance
and 4A sink current capability enable the lower gate driver to
absorb the current injected into the lower gate through the
drain-to-gate capacitor of the lower MOSFET and help
prevent shoot through caused by the self turn-on of the lower
MOSFET due to high dV/dt of the switching node.
not exceed either output’s turn-off propagation delay plus the
MOSFET gate discharge time to ~1V. Abnormally long PWM
signal transition times through the shutdown window will simply
introduce additional dead time between turn off and turn on of
the synchronous bridge’s MOSFETs. For optimal performance,
no more than 50pF parasitic capacitive load should be present
on the PWM line of ISL6596 (assuming an Intersil PWM
controller is used).
Bootstrap Considerations
This driver features an internal bootstrap diode. Simply
adding an external capacitor across the BOOT and PHASE
pins completes the bootstrap circuit.
The following equation helps select a proper bootstrap
capacitor size:
Q GATE
C BOOT_CAP ≥ -------------------------------------∆V BOOT_CAP
Q G1 • VCC
Q GATE = ------------------------------- • N Q1
V GS1
where QG1 is the amount of gate charge per upper MOSFET
at VGS1 gate-source voltage and NQ1 is the number of
control MOSFETs. The ∆VBOOT_CAP term is defined as the
allowable droop in the rail of the upper gate drive.
As an example, suppose two IRLR7821 FETs are chosen as
the upper MOSFETs. The gate charge, QG, from the data
sheet is 10nC at 4.5V (VGS) gate-source voltage. Then the
QGATE is calculated to be 22nC at VCC level. We will
assume a 200mV droop in drive voltage over the PWM
cycle. We find that a bootstrap capacitance of at least
0.110µF is required. The next larger standard value
capacitance is 0.22µF. A good quality ceramic capacitor is
recommended.
PWM Input and Threshold Control
6
1.8
1.6
1.4
1.2
1.0
0.8
QGATE = 100nC
0.6
nC
50
The ISL6596 also features the adaptable tri-state PWM input.
Once the PWM signal enters the shutdown window, either
MOSFET previously conducting is turned off. If the PWM signal
remains within the shutdown window for longer than the gate
turn-off propagation delay of the previously conducting
MOSFET, the output drivers are disabled and both MOSFET
gates are pulled and held low. The shutdown state is removed
when the PWM signal moves outside the shutdown window.
The PWM rising and falling thresholds outlined in the Electrical
Specifications determine when the lower and upper gates are
enabled. During normal operation in a typical application, the
PWM rise and fall times through the shutdown window should
2.0
CBOOT_CAP (µF)
A unique feature of the ISL6596 is the programmable PWM
logic threshold set by the control pin (VCTRL) voltage. The
VCTRL pin should connect to the VCC of the controller, thus
the PWM logic threshold follows with the voltage level of the
controller. For 5V applications, this pin can tie to the driver
VCC and simplify the routing.
(EQ. 1)
0.4
0.2
20nC
0.0
0.0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1.0
∆VBOOT_CAP (V)
FIGURE 2. BOOTSTRAP CAPACITANCE vs BOOT RIPPLE
VOLTAGE
FN9240.0
November 2, 2005
ISL6596
Power Dissipation
Package power dissipation is mainly a function of the
switching frequency (FSW), the output drive impedance, the
external gate resistance, and the selected MOSFET’s
internal gate resistance and total gate charge. Calculating
the power dissipation in the driver for a desired application is
critical to ensure safe operation. Exceeding the maximum
allowable power dissipation level will push the IC beyond the
maximum recommended operating junction temperature of
125°C. The maximum allowable IC power dissipation for the
SO8 package is approximately 800mW at room temperature,
while the power dissipation capacity in the DFN package,
with an exposed heat escape pad, is much higher. See
Layout Considerations paragraph for thermal transfer
improvement suggestions. When designing the driver into an
application, it is recommended that the following calculation
is used to ensure safe operation at the desired frequency for
the selected MOSFETs. The total gate drive power losses
due to the gate charge of MOSFETs and the driver’s internal
circuitry and their corresponding average driver current can
be estimated with Equations 2 and 3, respectively:
P Qg_TOT = P Qg_Q1 + P Qg_Q2 + I Q • VCC
(EQ. 2)
The total gate drive power losses are dissipated among the
resistive components along the transition path. The drive
resistance dissipates a portion of the total gate drive power
losses, the rest will be dissipated by the external gate
resistors (RG1 and RG2, should be a short to avoid
interfering with the operation shoot-through protection
circuitry) and the internal gate resistors (RGI1 and RGI2) of
MOSFETs. Figures 3 and 4 show the typical upper and lower
gate drives turn-on transition path. The power dissipation on
the driver can be roughly estimated as:
P DR = P DR_UP + P DR_LOW + I Q • VCC
R HI1
R LO1

 P Qg_Q1
P DR_UP =  -------------------------------------+ --------------------------------------- • --------------------2
 R HI1 + R EXT1 R LO1 + R EXT1
R LO2
R HI2

 P Qg_Q2
P DR_LOW =  -------------------------------------+ --------------------------------------- • --------------------2
 R HI2 + R EXT2 R LO2 + R EXT2
R GI2
R EXT2 = R G2 + ------------N
R GI1
R EXT2 = R G1 + ------------N
Q1
VCC
Q2
BOOT
D
Q G1 • VCC 2
P Qg_Q1 = ---------------------------------- • F SW • N Q1
V GS1
CGD
RHI1
Q G2 • VCC 2
P Qg_Q2 = ---------------------------------- • F SW • N Q2
V GS2
 Q G1 • N Q1 Q G2 • N Q2
- + ------------------------------ • VCC • F SW + I Q
I VCC =  ----------------------------V GS2 
 V GS1
(EQ. 4)
RLO1
G
UGATE
RG1
CDS
RGI1
CGS
Q1
S
PHASE
(EQ. 3)
where the gate charge (QG1 and QG2) is defined at a
particular gate to source voltage (VGS1and VGS2) in the
corresponding MOSFET datasheet; IQ is the driver’s total
quiescent current with no load at both drive outputs; NQ1
and NQ2 are the number of upper and lower MOSFETs,
respectively. The IQ VCC product is the quiescent power of
the driver without capacitive load and is typically negligible.
FIGURE 3. TYPICAL UPPER-GATE DRIVE TURN-ON PATH
VCC
D
CGD
RHI2
LGATE
RLO2
G
RG2
CDS
RGI2
CGS
GND
Q2
S
FIGURE 4. TYPICAL LOWER-GATE DRIVE TURN-ON PATH
7
FN9240.0
November 2, 2005
ISL6596
Application Information
Upper MOSFET Self Turn-On Effects At Startup
MOSFET Selection
Should the driver have insufficient bias voltage applied, its
outputs are floating. If the input bus is energized at a high
dV/dt rate while the driver outputs are floating, because of
self-coupling via the internal CGD of the MOSFET, the
UGATE could momentarily rise up to a level greater than the
threshold voltage of the MOSFET. This could potentially turn
on the upper switch and result in damaging inrush energy.
Therefore, if such a situation (when input bus powered up
before the bias of the controller and driver is ready) could
conceivably be encountered, it is a common practice to
place a resistor (RUGPH) across the gate and source of the
upper MOSFET to suppress the Miller coupling effect. The
value of the resistor depends mainly on the input voltage’s
rate of rise, the CGD/CGS ratio, as well as the gate-source
threshold of the upper MOSFET. A higher dV/dt, a lower
CDS/CGS ratio, and a lower gate-source threshold upper
FET will require a smaller resistor to diminish the effect of
the internal capacitive coupling. For most applications, a
5kΩ to 10kΩ resistor is typically sufficient, not affecting
normal performance and efficiency.
Layout Considerations
A good layout helps reduce the ringing on the switching
node (PHASE) and significantly lowers the stress applied to
the output drives. The following advice is meant to lead to an
optimized layout:
• Keep decoupling loops (VCC-GND and BOOT-PHASE) as
short as possible.
• Minimize trace inductance, especially on low-impedance
lines. All power traces (UGATE, PHASE, LGATE, GND,
VCC) should be short and wide, as much as possible.
• Minimize the inductance of the PHASE node. Ideally, the
source of the upper and the drain of the lower MOSFET
should be as close as thermally allowable.
• Minimize the current loop of the output and input power
trains. Short the source connection of the lower MOSFET
to ground as close to the transistor pin as feasible. Input
capacitors (especially ceramic decoupling) should be
placed as close to the drain of upper and source of lower
MOSFETs as possible.
In addition, for heat spreading, place copper underneath the
IC whether it has an exposed pad or not. The copper area
can be extended beyond the bottom area of the IC and/or
connected to buried power ground plane(s) with thermal
vias. This combination of vias for vertical heat escape,
extended copper plane, and buried planes improve heat
dissipation and allow the part to achieve its full thermal
potential.
The coupling effect can be roughly estimated with the
following equations, which assume a fixed linear input ramp
and neglect the clamping effect of the body diode of the
upper drive and the bootstrap capacitor. Other parasitic
components such as lead inductances and PCB
capacitances are also not taken into account. These
equations are provided for guidance purpose only.
Therefore, the actual coupling effect should be examined
using a very high impedance (10MΩ or greater) probe to
ensure a safe design margin.
–V
DS

----------------------------------
dV

-----⋅
R
⋅ C iss
dV

V GS_MILLER = ------- ⋅ R ⋅ C rss  1 – e dt


dt




R = R UGPH + R GI
VCC
(EQ. 5)
C iss = C GD + C GS
C rss = C GD
VIN
BOOT
D
CBOOT
CGD
DU
DL
UGATE
RUGPH
The D2-PAK, or D-PAK packaged MOSFETs, have large
parasitic lead inductances and are not recommended unless
additional circuits are implemented to prevent the BOOT and
PHASE pins from exceeding the device rating. Low-profile
MOSFETs, such as Direct FETs and multi-SOURCE leads
devices (SO-8, LFPAK, PowerPAK), have low parasitic lead
inductances and are preferred.
ISL6596
The parasitic inductances of the PCB and of the power
devices’ packaging (both upper and lower MOSFETs) can
cause serious ringing, exceeding absolute maximum rating
of the devices. The negative ringing at the edges of the
PHASE node could increase the bootstrap capacitor voltage
through the internal bootstrap diode, and in some cases, it
may overstress the upper MOSFET driver. Careful layout,
proper selection of MOSFETs and packaging can go a long
way toward minimizing such unwanted stress.
G
CDS
RGI
CGS
QUPPER
S
PHASE
FIGURE 5. GATE TO SOURCE RESISTOR TO REDUCE
UPPER MOSFET MILLER COUPLING
8
FN9240.0
November 2, 2005
ISL6596
Dual Flat No-Lead Plastic Package (DFN)
2X
0.15 C A
D
A
L10.3x3
10 LEAD DUAL FLAT NO-LEAD PLASTIC PACKAGE
MILLIMETERS
2X
0.15 C B
E
6
INDEX
AREA
SYMBOL
MIN
0.80
0.90
1.00
-
-
-
0.05
-
0.28
5,8
2.05
7,8
1.65
7,8
0.20 REF
0.18
D
1.95
E
SIDE VIEW
C
SEATING
PLANE
A3
1
e
1.60
-
0.50 BSC
-
k
0.25
-
-
L
0.30
0.35
0.40
N
10
Nd
5
8
2
3
1. Dimensioning and tolerancing conform to ASME Y14.5-1994.
2. N is the number of terminals.
NX k
E2/2
N-1
7. Dimensions D2 and E2 are for the exposed pads which provide
improved electrical and thermal performance.
NX b
5
(Nd-1)Xe
REF.
4. All dimensions are in millimeters. Angles are in degrees.
6. The configuration of the pin #1 identifier is optional, but must be
located within the zone indicated. The pin #1 identifier may be
either a mold or mark feature.
NX L
e
3. Nd refers to the number of terminals on D.
5. Dimension b applies to the metallized terminal and is measured
between 0.15mm and 0.30mm from the terminal tip.
E2
8
1.55
NOTES:
D2/2
2
N
-
Rev. 3 6/04
D2
(DATUM B)
2.00
8
7
6
INDEX
AREA
(DATUM A)
0.08 C
-
3.00 BSC
E2
0.10 C
0.23
3.00 BSC
D2
A
NOTES
A
A3
B
MAX
A1
b
TOP VIEW
NOMINAL
0.10 M C A B
8. Nominal dimensions are provided to assist with PCB Land
Pattern Design efforts, see Intersil Technical Brief TB389.
BOTTOM VIEW
C
L
0.415
NX (b)
(A1)
0.200
5
L
NX L
e
SECTION "C-C"
C
NX b
C C
TERMINAL TIP
FOR ODD TERMINAL/SIDE
9
FN9240.0
November 2, 2005
ISL6596
Small Outline Plastic Packages (SOIC)
M8.15 (JEDEC MS-012-AA ISSUE C)
N
INDEX
AREA
8 LEAD NARROW BODY SMALL OUTLINE PLASTIC PACKAGE
H
0.25(0.010) M
B M
INCHES
E
SYMBOL
-B1
2
3
L
SEATING PLANE
-A-
A
D
h x 45°
-C-
e
A1
B
0.25(0.010) M
C
0.10(0.004)
C A M
MIN
MAX
MIN
MAX
NOTES
A
0.0532
0.0688
1.35
1.75
-
A1
0.0040
0.0098
0.10
0.25
-
B
0.013
0.020
0.33
0.51
9
C
0.0075
0.0098
0.19
0.25
-
D
0.1890
0.1968
4.80
5.00
3
E
0.1497
0.1574
3.80
4.00
4
e
α
B S
0.050 BSC
1.27 BSC
-
H
0.2284
0.2440
5.80
6.20
-
h
0.0099
0.0196
0.25
0.50
5
L
0.016
0.050
0.40
1.27
6
N
α
NOTES:
MILLIMETERS
8
0°
8
8°
0°
7
8°
1. Symbols are defined in the “MO Series Symbol List” in Section 2.2 of
Publication Number 95.
Rev. 1 6/05
2. Dimensioning and tolerancing per ANSI Y14.5M-1982.
3. Dimension “D” does not include mold flash, protrusions or gate burrs.
Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006
inch) per side.
4. Dimension “E” does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm (0.010 inch) per
side.
5. The chamfer on the body is optional. If it is not present, a visual index
feature must be located within the crosshatched area.
6. “L” is the length of terminal for soldering to a substrate.
7. “N” is the number of terminal positions.
8. Terminal numbers are shown for reference only.
9. The lead width “B”, as measured 0.36mm (0.014 inch) or greater
above the seating plane, shall not exceed a maximum value of
0.61mm (0.024 inch).
10. Controlling dimension: MILLIMETER. Converted inch dimensions
are not necessarily exact.
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10
FN9240.0
November 2, 2005