1
Synchronous Step-Down MOSFET Drivers
ZL1505
The ZL1505 is an integrated high-speed, high-current
N-channel MOSFET driver for synchronous step-down DC/DC
conversion applications. When used with Zilker Labs Digital-
DC™ PWM controllers, the ZL1505 enables dynamically
adaptive dead-time control that optimizes efficiency under all
operating conditions. A dual input PWM configuration enables
this efficiency optimization while minimizing complexity within
the driver.
Operating from a 4.5V to 7.5V input, the ZL1505 combines a
5A, 0.5W low-side driver and a 3A, 0.8W high-side driver to
support high step-down buck applications. A unique adjustable
gate drive current scheme allows the user to adjust the drive
current on both drivers to optimize performance for a wide
rage of input/output voltages, load currents, power MOSFETs
and switching frequencies up to 1.4MHz. An integrated 30V
bootstrap Schottky diode is used to charge the external
bootstrap capacitor. An internal watchdog circuit prevents
excessive shoot-through currents and protects the external
MOSFET switches.
The ZL1505 is specified over a wide -40°C to +125°C junction
temperature range and is available in an exposed pad DFN-10
package.
Features
• High-speed, high-current drivers for synchronous N-channel
MOSFETs
• Adaptive dead-time control optimizes efficiency when used
with Digital-DC controllers
• Integrated 30V bootstrap Schottky diode
• Capable of driving 40A per phase
• Supports switching frequency up to 1.4MHz
- >4A source, >5A sink low-side driver
- >3A source/sink high-side driver
- <10ns rise/fall times, low propagation delay
• Adjustable gate drive strength optimizes efficiency for
different V
IN
, V
OUT
, I
OUT
, F
SW
and MOSFET combinations
• Internal non-overlap watchdog prevents shoot-through
currents
Applications*(see page 12)
• High efficiency, high-current DC/DC buck converters with
digital control and PMBus™
• Multi-phase digital DC/DC converters with phase
adding/dropping
•Power train modules
• Synchronous rectification for secondary side isolated power
converters
Related Literature*(see page 12)
• ZL2004 Adaptive Digital DC/DC Controller with Current
Sharing
FIGURE 1. ZL1505 BLOCK DIAGRAM
VDD
BST
GH
SW
ZL1505
GL
LEVEL
SHIFT
SHOOT-
THROUGH
PROTECTION
PWMH
PWML
GND
VDD
LSEL
HSEL
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
|Copyright Intersil Americas Inc. 2009-2011. All Rights Reserved
Intersil (and design) is a trademark owned by Intersil Corporation or one of its subsidiaries.
All other trademarks mentioned are the property of their respective owners.
February 25, 2011
FN6845.3
