XRP7708_12 Datasheet, PDF (1/28 Pages) Exar Corporation – Quad Channel Digital PWM Step Down Controllers

April 2012
XRP7708 and XRP7740
Quad Channel Digital PWM Step Down Controllers
Rev. 1.2.2
GENERAL DESCRIPTION
The XRP7708 and XRP7740 are quad-output
pulse-width modulated (PWM) step-down DC-
DC controllers with a built-in LDO for standby
power and GPIOs. The devices provide a
complete power management solution in one
IC and are fully programmable via an I²C
serial interface. Independent Digital Pulse
Width Modulator (DPWM) channels regulate
output voltages and provide all required
protection functions such as current limiting
and over-voltage protection.
Each output voltage can be programmed from
0.9V to 5.1V without the need of an external
voltage divider. The wide range of the
programmable DPWM switching frequency
(from 300 KHz to 1.5 MHz) enables the user to
optimize between efficiency and component
size. Input voltage range is from 6.5V to 20V.
An I²C bus interface is provided to program
the IC as well as to communicate with the host
for fault reporting and handling, power rail
parameters monitoring, etc.
The device offers a complete solution for soft-
start and soft-stop. The start-up delay and
ramp of each PWM regulator can be
independently controlled. The device can start
up a pre-biased PWM channel without causing
large negative inductor current.
TYPICAL APPLICATION DIAGRAM
APPLICATIONS
• Multi Channel Programmable
Power Supplies
• Audio-Video Equipment
• Industrial & Telecom Equipment
• Processors & DSPs Based Equipment
FEATURES
• 4 Channel Step Down Controller
− 3ohm/1.8ohm driver – XRP7740
− 5ohm/1.8ohm driver – XRP7708
− Programmable Output Voltage 0.9V-5.1V
− Programmable 1.5MHz DPWM Frequency
• 6.5V-20V Single Input Voltage Range
• Up to 6 Reconfigurable GPIO Pins
• Fully Programmable via I2C Interface
• Independent Digital Pulse Width
Modulator (DPWM) channels
• Complete Monitoring and Reporting
• Complete Power Up/Down Sequencing
• Full On Board Protection
OTP, UVLO, OCP and OVP
• Built-in 3.3V/5V LDO
• PowerArchitect™ Design Software
• Green/Halogen Free 40-pin TQFN
XRP7708
XRP7740
Exposed Pad: AGND
Fig. 1: XRP7708 or XRP7740 Application Diagram
Exar Corporation
48720 Kato Road, Fremont CA 94538, USA
www.exar.com
Tel. [phone] – Fax. [phone]