DATASHEET
ISL95808
FN8689
Rev 2.00
High Voltage Synchronous Rectified Buck MOSFET Driver
May 25, 2016
The ISL95808 is a high frequency, dual MOSFET driver with low
Features
shutdown current, optimized to drive two N-Channel power
Dual MOSFET drivers for synchronous rectified bridge
MOSFETs in a synchronous-rectified buck converter topology. It
is especially suited for mobile computing applications that
Adaptive shoot-through protection
require high efficiency and excellent thermal performance. The
0.5 ON-resistance and 4A sink current capability
driver, combined with an Intersil multiphase Buck PWM
Supports high switching frequency up to 2MHz
controller, forms a complete single-stage core-voltage
- Fast output rise and fall time
regulator solution for advanced mobile microprocessors.
- Low propagation delay
The ISL95808 features a 4A typical sinking current for the
Three-state PWM input for power stage shutdown
lower gate driver. This current is capable of holding the lower
MOSFET gate off during the rising edge of the phase node. This
Internal bootstrap Schottky diode
prevents shoot-through power loss caused by the high dv/dt of
Low shutdown supply current (5V, 3A)
phase voltages. The operating voltage matches the 30V
Diode emulation for enhanced light-load efficiency and
breakdown voltage of the MOSFETs commonly used in mobile
prebiased start-up applications
computer power supplies.
VCC POR (Power-On Reset) feature integrated
The ISL95808 also features a three-state PWM input. This
Low three-state shutdown hold-off time (typical 160ns)
PWM input, working together with Intersils multiphase PWM
controllers, will prevent negative voltage output during CPU
DFN package
shutdown. This feature eliminates a protective Schottky diode
Pb-free (RoHS compliant)
usually seen in microprocessor power systems.
MOSFET gates can be efficiently switched up to 2MHz using Applications
the ISL95808. Each driver is capable of driving a 3000pF load
Core voltage supplies for Intel and AMD mobile
with propagation delays of 8ns and transition times under
microprocessors
10ns. Bootstrapping is implemented with an internal Schottky
High frequency low profile DC/DC converters
diode. This reduces system cost and complexity, while allowing
for the use of higher performance MOSFETs. Adaptive
High current low output voltage DC/DC converters
shoot--through protection is integrated to prevent both
High input voltage DC/DC converters
MOSFETs from conducting simultaneously.
A diode emulation feature is integrated in the ISL95808 to
Related Literature
enhance converter efficiency at light load conditions. This
TB389, PCB Land Pattern Design and Surface Mount
feature also allows for monotonic start-up into prebiased
Guidelines for MLFP Packages
outputs. When diode emulation is enabled, the driver will allow
discontinuous conduction mode by detecting when the TB447, Guidelines for Preventing Boot-to-Phase Stress on
inductor current reaches zero and subsequently turning off the Half-Bridge MOSFET Driver ICs
low-side MOSFET gate.
The ISL95808 also features very low shutdown supply current
(5V, 3A) to ensure the low power consumption.
VCC
BOOT
FCCM
UGATE
PHASE
SHOOT-
THROUGH
PROTECTION
VCC
CONTROL
PWM
LOGIC
10k LGATE
GND
THERMAL PAD
FIGURE 1. BLOCK DIAGRAM
FN8689 Rev 2.00 Page 1 of 9
May 25, 2016ISL95808
Ordering Information
PART NUMBER PART TEMP. RANGE TAPE AND REEL PACKAGE PKG.
(Notes 1, 2, 3) MARKING (C) (UNITS) (RoHS Compliant) DWG. #
ISL95808HRZ-T 08 -10 to +100 6k 8 Ld 2x2 DFN L8.2x2D
ISL95808IRZ-T 08I -40 to +100 6k 8 Ld 2x2 DFN L8.2x2D
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.
Pin Configuration
ISL95808
(8 LD 2x2 DFN)
TOP VIEW
6
UGATE 1 8 PHASE
2
BOOT 7 FCCM
6
PWM 3 6 VCC
4
GND 5 LGATE
Pin Descriptions
PIN NUMBER PIN NAME DESCRIPTION
1 UGATE The UGATE pin is the upper gate drive output. Connect to the gate of high-side power N-Channel MOSFET.
2 BOOT 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.
3 PWM 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.
4 GND GND is the ground pin for the IC.
5 LGATE LGATE is the lower gate drive output. Connect to gate of the low-side power N-Channel MOSFET.
6 VCC 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.
7 FCCM 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.
8 PHASE 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.
FN8689 Rev 2.00 Page 2 of 9
May 25, 2016