XXRRPP77770088 aanndd XXRRPP77774400 QQuuaadd CChhaannnneell DDiiggiittaall PPWWMM SStteepp DDoowwnn CCoonnttrroolllleerrss April 2012 Rev. 1.2.2 GENERAL DESCRIPTION APPLICATIONS The XRP7708 and XRP7740 are quad-output Multi Channel Programmable pulse-width modulated (PWM) step-down DC- Power Supplies DC controllers with a built-in LDO for standby Audio-Video Equipment power and GPIOs. The devices provide a Industrial & Telecom Equipment complete power management solution in one 2 Processors & DSPs Based Equipment IC and are fully programmable via an I C serial interface. Independent Digital Pulse FEATURES Width Modulator (DPWM) channels regulate output voltages and provide all required 4 Channel Step Down Controller protection functions such as current limiting 3ohm/1.8ohm driver XRP7740 and over-voltage protection. 5ohm/1.8ohm driver XRP7708 Each output voltage can be programmed from Programmable Output Voltage 0.9V-5.1V 0.9V to 5.1V without the need of an external Programmable 1.5MHz DPWM Frequency voltage divider. The wide range of the programmable DPWM switching frequency 6.5V-20V Single Input Voltage Range (from 300 KHz to 1.5 MHz) enables the user to Up to 6 Reconfigurable GPIO Pins optimize between efficiency and component Fully Programmable via I2C Interface size. Input voltage range is from 6.5V to 20V. 2 Independent Digital Pulse Width An I C bus interface is provided to program Modulator (DPWM) channels the IC as well as to communicate with the host for fault reporting and handling, power rail Complete Monitoring and Reporting parameters monitoring, etc. Complete Power Up/Down Sequencing The device offers a complete solution for soft- Full On Board Protection start and soft-stop. The start-up delay and OTP, UVLO, OCP and OVP ramp of each PWM regulator can be Built-in 3.3V/5V LDO independently controlled. The device can start PowerArchitect Design Software up a pre-biased PWM channel without causing Green/Halogen Free 40-pin TQFN large negative inductor current. TYPICAL APPLICATION DIAGRAM XRP7708 XRP7740 Exposed Pad: AGND Fig. 1: XRP7708 or XRP7740 Application Diagram Exar Corporation www.exar.com 48720 Kato Road, Fremont CA 94538, USA Tel. +1 510 668-7000 Fax. +1 510 668-7001 XXRRPP77770088 aanndd XXRRPP77774400 QQuuaadd CChhaannnneell DDiiggiittaall PPWWMM SStteepp DDoowwnn CCoonnttrroolllleerrss ABSOLUTE MAXIMUM RATINGS OPERATING RATINGS Operating Input Voltage VIN ........................ 6.5V to 20V These are stress ratings only and functional operation of X the device at these ratings or any other above those Junction Temperature Range .................... -40C to 125C indicated in the operation sections of the specifications Thermal Resistance ....................................24.3C/W JA below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. VCCA, VCCD, LDOOUT, GLx, VOUTx ............................ 6V AVDD, DVDD ........................................................ 2.0V VIN1, VIN2 ............................................................ 22V LXx .............................................................. -1V to 22V Logic Inputs ............................................................. 6V BSTx, GHx .................................................... VLXx + 5V Storage Temperature .............................. -65C to 150C Lead Temperature (Soldering, 10 sec) ................... 300C ELECTRICAL SPECIFICATIONS Specifications with standard type are for an Operating Junction Temperature of T = 25C only limits applying over the full J Operating Junction Temperature range are denoted by a . Minimum and Maximum limits are guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at T = 25C, and are provided for J reference purposes only. Unless otherwise indicated, VIN = 6.5V to 20V, VIN = 6.5V to 20V, Enable=HIGH, 1 2 C = C = 1nF. GL GH Quiescent Current Parameter Min. Typ. Max. Units Conditions LDOOUT enabled (no load) No switching converter channels enabled VIN Supply Current in STANDBY 9 mA 2 I C communication active Switching frequency = 400kHz VIN Supply Current in 180 A EN=0V, VIN1=VIN2=12V SHUTDOWN 4 channels running, VIN Supply Current 28 mA GH and GH = 1nF load each VIN=12V, Switching frequency = 300kHz 4 channels running, VIN Supply Current 50 mA GH and GH = 1nF load each VIN=12V, Switching frequency = 1MHz Step Down Controllers Parameter Min. Typ. Max. Units Conditions 20 mV 0.9V VOUT 2.5V -20 VOUT Regulation Accuracy 40 mV 2.6V VOUT 5.1V -40 1 VOUT regulation range 0.9 5.1 Programmable range of each channel VOUT set point resolution 50 0.9V VOUT 2.5V VOUT set point resolution 100 2.6V VOUT 5.1V VOUT Input Current 1 uA 0.9V < VOUT <= 2.5V VOUT Input Resistance 2.6V VOUT 5.1V 120 k Note 1: Voltages above 5.1V can be obtained by using an external voltage divider. 2012 Exar Corporation 2/28 Rev. 1.2.2