DATASHEET
ISL95808
High Voltage Synchronous Rectified Buck MOSFET Driver
The
ISL95808
is a high frequency, dual MOSFET driver with low
shutdown current, optimized to drive two N-Channel power
MOSFETs in a synchronous-rectified buck converter topology. It
is especially suited for mobile computing applications that
require high efficiency and excellent thermal performance. The
driver, combined with an Intersil multiphase Buck PWM
controller, forms a complete single-stage core-voltage
regulator solution for advanced mobile microprocessors.
The ISL95808 features a 4A typical sinking current for the
lower gate driver. This current is capable of holding the lower
MOSFET gate off during the rising edge of the phase node. This
prevents shoot-through power loss caused by the high dv/dt of
phase voltages. The operating voltage matches the 30V
breakdown voltage of the MOSFETs commonly used in mobile
computer power supplies.
The ISL95808 also features a three-state PWM input. This
PWM input, working together with Intersil’s multiphase PWM
controllers, will prevent negative voltage output during CPU
shutdown. This feature eliminates a protective Schottky diode
usually seen in microprocessor power systems.
MOSFET gates can be efficiently switched up to 2MHz using
the ISL95808. Each driver is capable of driving a 3000pF load
with propagation delays of 8ns and transition times under
10ns. Bootstrapping is implemented with an internal Schottky
diode. This reduces system cost and complexity, while allowing
for the use of higher performance MOSFETs. Adaptive
shoot--through protection is integrated to prevent both
MOSFETs from conducting simultaneously.
A diode emulation feature is integrated in the ISL95808 to
enhance converter efficiency at light load conditions. This
feature also allows for monotonic start-up into prebiased
outputs. When diode emulation is enabled, the driver will allow
discontinuous conduction mode by detecting when the
inductor current reaches zero and subsequently turning off the
low-side MOSFET gate.
The ISL95808 also features very low shutdown supply current
(5V, 3µA) to ensure the low power consumption.
FN8689
Rev 2.00
May 25, 2016
Features
• Dual MOSFET drivers for synchronous rectified bridge
• Adaptive shoot-through protection
• 0.5Ω ON-resistance and 4A sink current capability
• Supports high switching frequency up to 2MHz
- Fast output rise and fall time
- Low propagation delay
• Three-state PWM input for power stage shutdown
• Internal bootstrap Schottky diode
• Low shutdown supply current (5V, 3µA)
• Diode emulation for enhanced light-load efficiency and
prebiased start-up applications
• VCC POR (Power-On Reset) feature integrated
• Low three-state shutdown hold-off time (typical 160ns)
• DFN package
• Pb-free (RoHS compliant)
Applications
• Core voltage supplies for Intel® and AMD™ mobile
microprocessors
• High frequency low profile DC/DC converters
• High current low output voltage DC/DC converters
• High input voltage DC/DC converters
Related Literature
•
TB389,
“PCB Land Pattern Design and Surface Mount
Guidelines for MLFP Packages”
•
TB447,
“Guidelines for Preventing Boot-to-Phase Stress on
Half-Bridge MOSFET Driver ICs”
VCC
FCCM
SHOOT-
THROUGH
PROTECTION
PWM
10kΩ
CONTROL
LOGIC
BOOT
UGATE
PHASE
VCC
LGATE
GND
THERMAL PAD
FIGURE 1. BLOCK DIAGRAM
FN8689 Rev 2.00
May 25, 2016
Page 1 of 9
ISL95808
Ordering Information
PART NUMBER
(Notes
1, 2, 3)
ISL95808HRZ-T
ISL95808IRZ-T
NOTES:
1. Please refer to
TB347
for details on reel specifications.
2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte
tin plate plus anneal (e3 termination finish, which is 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.
3. For Moisture Sensitivity Level (MSL), please see product information page for
ISL95808.
For more information on MSL, please see tech brief
TB363.
08
08I
PART
MARKING
TEMP. RANGE
(°C)
-10 to +100
-40 to +100
TAPE AND REEL
(UNITS)
6k
6k
PACKAGE
(RoHS Compliant)
8 Ld 2x2 DFN
8 Ld 2x2 DFN
PKG.
DWG. #
L8.2x2D
L8.2x2D
Pin Configuration
ISL95808
(8 LD 2x2 DFN)
TOP VIEW
UGATE 1
BOOT 2
PWM 3
GND 4
6
8 PHASE
7 FCCM
6
6 VCC
5 LGATE
Pin Descriptions
PIN NUMBER
1
2
PIN NAME
UGATE
BOOT
DESCRIPTION
The UGATE pin is the upper gate drive output. Connect to the gate of high-side power N-Channel MOSFET.
BOOT is the floating bootstrap supply pin for the upper gate drive. Connect the bootstrap capacitor between this
pin and the PHASE pin. The bootstrap capacitor provides the charge to turn on the upper MOSFET. See
“Internal
Bootstrap Diode” on page 7
for guidance in choosing the appropriate capacitor value.
The PWM signal is the control input for the driver. The PWM signal can enter three distinct states during operation.
See
“Three-State PWM Input” on page 6
for further details. Connect this pin to the PWM output of the controller.
GND is the ground pin for the IC.
LGATE is the lower gate drive output. Connect to gate of the low-side power N-Channel MOSFET.
Connect the VCC pin to a +5V bias supply. Place a high quality bypass capacitor from this pin to GND. The VCC
pin of the driver(s) and related VCC or +5V bias supply pin of the Intersil controller must share a common +5V
supply.
The FCCM pin enables or disables diode emulation. When FCCM is LOW, diode emulation is allowed. When
FCCM is HIGH, continuous conduction mode is forced. See
“Diode Emulation” on page 6
for more detail. High
impedance on the input of FCCM will shut down ISL95808.
Connect the PHASE pin to the source of the upper MOSFET and the drain of the lower MOSFET. This pin provides
a return path for the upper gate driver.
3
4
5
6
PWM
GND
LGATE
VCC
7
FCCM
8
PHASE
FN8689 Rev 2.00
May 25, 2016
Page 2 of 9
ISL95808
Absolute Maximum Ratings
i
Thermal Information
Thermal Resistance (Typical)
JA
(°C/W)
JC
(°C/W)
8 Ld 2x2 DFN Package (Notes
5, 6)
. . . . . .
87
22
Maximum Storage Temperature Range . . . . . . . . . . . . . .-65°C to +150°C
Pb-free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see
TB493
Supply Voltage (VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to 7V
Input Voltage (V
FCCM
, V
PWM
) . . . . . . . . . . . . . . . . . . . . -0.3V to VCC + 0.3V
BOOT Voltage (V
BOOT-GND
) . . . . . . . . . . . . . . . -0.3V to 33V or 36V (<20ns)
BOOT To PHASE Voltage (V
BOOT-PHASE
). . . . . . . . . . . . . . . . -0.3V to 7V (DC)
-0.3V to 9V (<10ns)
PHASE Voltage (Note
4)
. . . . . . . . . . . . . . . . . . . . . . . . . . (GND - 0.3V) to 30V
GND - 8V (<20ns Pulse Width, 10µJ)
UGATE Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . V
PHASE
- 0.3V (DC) to V
BOOT
V
PHASE
- 5V (<20ns Pulse Width, 10µJ) to V
BOOT
LGATE Voltage . . . . . . . . . . . . . . . . . . . . . . . . .GND - 0.3V (DC) to VCC + 0.3V
GND - 2.5V (<20ns Pulse Width, 5µJ) to VCC + 0.3V
Recommended Operating Conditions
Ambient Temperature
HRZ. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-10°C to +100°C
IRZ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-40°C to +100°C
Maximum Operating Junction Temperature . . . . . . . . . . . . . . . . . . +125°C
Supply Voltage, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V ±10%
CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product
reliability and result in failures not covered by warranty.
NOTES:
4. The Phase Voltage is capable of withstanding -7V when the BOOT pin is at GND.
5.
JA
is measured in free air with the component mounted on a high effective thermal conductivity test board with “direct attach” features. See Tech
Brief
TB379.
6. For
JC
, the “case temp” location is the center of the exposed metal pad on the package underside.
Recommended Operating Conditions, Unless Otherwise Noted. Boldface limits apply across the operating
temperature range T
A
= -40°C to +100°C for Industrial (IRZ) and T
A
= -10°C to +100°C for Hi-Temp Commercial (HRZ).
SYMBOL
V
CC
SUPPLY CURRENT
I
VCCSD
I
VCC
Shutdown Bias Supply Current
Operating Bias Supply Current
PWM and FCCM pin floating
PWM pin floating, V
FCCM
= 5V
PWM pin floating, V
FCCM
= 0V
POR
V
CC
Rising
HRZ
IRZ
Hysteresis
BOOTSTRAP DIODE
HRZ
IRZ
PWM INPUT
I
PWM
Input Current
V
PWM
= 5V
V
PWM
= 0V
PWM Three-State Rising Threshold
PWM Three-State Falling Threshold
HRZ
IRZ
FCCM INPUT
I
FCCM
Input Current
V
FCCM
= 5V
V
FCCM
= 0V
FCCM Shutdown Rising Threshold
V
VCC
= 5V
-
-
1.4
50
50
1.8
-
-
2.2
µA
µA
V
Three-State Shutdown Hold-Off Time
V
VCC
= 5V
V
VCC
= 5V
V
VCC
= 5V, temperature = +25°C
V
VCC
= 5V, temperature = +25°C
-
-
0.70
3.5
100
85
250
-250
1.00
3.8
175
175
-
-
1.30
4.1
250
250
µA
µA
V
V
ns
ns
Forward Voltage
V
VCC
= 5V, forward bias current = 2mA
V
VCC
= 5V, forward bias current = 2mA
0.43
0.43
0.55
0.55
0.65
0.70
V
V
V
CC
Falling
-
2.40
2.39
-
3.40
2.90
2.90
500
3.90
-
-
-
V
V
V
mV
-
-
-
3.3
80
120
4
-
-
µA
µA
µA
PARAMETER
TEST CONDITIONS
MIN
(Note
8)
TYP
MAX
(Note
8)
UNIT
Electrical Specifications
FN8689 Rev 2.00
May 25, 2016
Page 3 of 9
ISL95808
Recommended Operating Conditions, Unless Otherwise Noted. Boldface limits apply across the operating
temperature range T
A
= -40°C to +100°C for Industrial (IRZ) and T
A
= -10°C to +100°C for Hi-Temp Commercial (HRZ). (Continued)
SYMBOL
PARAMETER
FCCM Shutdown Falling Threshold
t
PS4EXIT
PS4 Exit Latency
V
VCC
= 5V
V
VCC
= 5V
TEST CONDITIONS
MIN
(Note
8)
2.8
-
TYP
3.2
MAX
(Note
8)
3.6
15
UNIT
V
µs
Electrical Specifications
SWITCHING TIME
t
RU
t
RL
t
FU
t
FL
t
PDLU
t
PDLL
t
PDHU
t
PDHL
t
PTS
t
LGMIN
UGATE Rise Time (Note
7)
LGATE Rise Time (Note
7)
UGATE Fall Time (Note
7)
LGATE Fall Time (Note
7)
UGATE Turn-Off Propagation Delay
LGATE Turn-Off Propagation Delay
UGATE Turn-On Propagation Delay
LGATE Turn-On Propagation Delay
UG/LG Three-State Propagation Delay
Minimum LG On-Time in DCM
V
VCC
= 5V, 3nF load
V
VCC
= 5V, 3nF load
V
VCC
= 5V, 3nF load
V
VCC
= 5V, 3nF load
V
VCC
= 5V, outputs unloaded
V
VCC
= 5V, outputs unloaded
V
VCC
= 5V, outputs unloaded
V
VCC
= 5V, outputs unloaded
V
VCC
= 5V, outputs unloaded
-
-
-
-
-
-
-
-
-
-
8.0
8.0
8.0
4.0
18
25
20
20
35
350
-
-
-
-
-
-
-
-
-
-
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
OUTPUT (Note
7)
R
U
I
U
R
U
I
U
R
L
I
L
R
L
I
L
NOTES:
7. Limits established by characterization and are not production tested.
8. Parameters with MIN and/or MAX limits are 100% tested at +25°C, unless otherwise specified. Temperature limits established by characterization
and are not production tested.
Upper Drive Source Resistance
Upper Driver Source Current
Upper Drive Sink Resistance
Upper Driver Sink Current
Lower Drive Source Resistance
Lower Driver Source Current
Lower Drive Sink Resistance
Lower Driver Sink Current
500mA source current
V
UGATE-PHASE
= 2.5V
500mA sink current
V
UGATE-PHASE
= 2.5V
500mA source current
V
LGATE
= 2.5V
500mA sink current
V
LGATE
= 2.5V
-
-
-
-
-
-
-
-
1
2.00
1
2.00
1
2.00
0.5
4.00
2.5
-
2.5
-
2.5
-
1.0
-
Ω
A
Ω
A
Ω
A
Ω
A
FN8689 Rev 2.00
May 25, 2016
Page 4 of 9
ISL95808
Typical Application With 2-Phase Converter
+5V
+5V
VCC
FCCM
PWM1
PWM2
FCCM
MAIN
CONTROL
ISEN1
ISEN2
+5V
VCC
BOOT
FCCM
GND
PWM
DRIVE
ISL95808
UGATE
PHASE
V
IN
PWM
DRIVE
ISL95808
THERMAL
PAD
BOOT
UGATE
PHASE
LGATE
V
IN
+V
CORE
VCC
THERMAL LGATE
PAD
FIGURE 2. TYPICAL APPLICATION WITH 2-PHASE CONVERTER
PS4 Exit Timing Diagram
5V
PWM
t
PS4EXIT
UGATE
5V
FCCM
2.5V
FIGURE 3. PS4 EXIT TIMING DIAGRAM
FN8689 Rev 2.00
May 25, 2016
Page 5 of 9
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