XRP7740 Datasheet, PDF (1/31 Pages) Exar Corporation – Quad-Output Digital PWM Buck Controller Supporting high current loads

September 2009
XRP7740
Quad-Output Digital PWM Buck Controller
Supporting high current loads
REV 1.1.0
GENERAL DESCRIPTION
The XRP7740 is a quad-output pulse-width modulated
(PWM) step-down DC-DC controller with a built-in LDO for
standby power and GPIOs. The device provides a complete
power management solution in one IC and is fully
programmable via the included 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. Two controllers support a load of up to
5A, while the other two controllers support up to 15A.
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.
APPLICATIONS
ƒ Computing: Servers, Storage Systems
ƒ Consumer: Set-top box (STB), Game Systems
ƒ Industrial: ATE, DC-DC converters, Video Processing
ƒ Plasma Display Panel (PDP)
ƒ Networking and Telecommunications Equipment
KEY FEATURES
ƒ Four switching buck (step-down) controllers each with
internal FET drivers. Two controllers (2 & 4) support loads
up to 15A; two controllers (1 & 3) support load up to 5A.
ƒ 6.5V to 20V input voltage range – no additional voltage
rails required
ƒ Output voltages programmable from 0.9V to 5.1V
ƒ Up to 6 reconfigurable GPIO pins
ƒ Fully programmable via I²C interface
ƒ Independent Digital Pulse Width Modulator (DPWM)
channels with five coefficient PID control
ƒ High Integration: elimination of external circuits and
components required for compensation, parameter
adjustment and interface
ƒ Programmable DPWM frequency range (300 kHz to 1.5
MHz) enables efficiency and component size optimization
ƒ Complete power monitoring and reporting
ƒ Independently controlled start-up delay and ramp for each
regulator, including soft start with a pre-biased load
voltage
ƒ Independently controlled soft-stop delay and ramp for
each regulator with a programmable stop voltage
ƒ Over-temperature protection (OTP) and Under Voltage
Lockout (UVLO); per-channel over-current protection
(OCP) and over-voltage protection (OVP)
ƒ Built-in LDO (configurable to 3.3V or 5V) with over-current
protection
ƒ Non-volatile memory for system configuration
ƒ Configuration development tools
Exar Corporation 48720 Kato Road, Fremont CA, 94538 • [phone] • FAX [phone] • www.exar.com
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