IR3081 International Rectifier Corp., IR3081 Datasheet - Page 5

• Manufacturer Part Number: IR3081
• Description: Xphasetm Vr 10 Control Ic
• Manufacturer: International Rectifier Corp.

PIN DESCRIPTION
PIN#
11,12
Page 5 of 39
8, 9,
2-7
10
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
1
PIN SYMBOL
RMPOUT
ENABLE
VOSNS-
PWRGD
OSCDS
TRM1-4
SS/DEL
OCSET
EAOUT
VID0-5
VBIAS
ROSC
VDAC
VDRP
LGND
BBFB
VCC
N/C
IIN
FB
PIN DESCRIPTION
Apply a voltage greater than VBIAS to disable the oscillator. Used during factory
testing & trimming. Ground or leave open for normal operation.
Inputs to VID D to A Converter
Used for precision post-package trimming of the VDAC voltage. Do not make any
connection to these pins.
Remote Sense Input. Connect to ground at the Load.
Connect a resistor to VOSNS- to program oscillator frequency and FB, OCSET,
BBFB, and VDAC bias currents
Regulated voltage programmed by the VID inputs. Current Sensing and PWM
operation are referenced to this pin. Connect an external RC network to VOSNS- to
program Dynamic VID slew rate.
Programs the hiccup over-current threshold through an external resistor tied to
VDAC and an internal current source. Over-current protection can be disabled by
connecting this pin to a DC voltage no greater than 6.5V (do not float this pin as
improper operation will occur).
Current Sense input from the Phase IC(s). To ensure proper operation bias to at
least 250mV (don’t float this pin).
Buffered IIN signal. Connect an external RC network to FB to program converter
output impedance
Inverting input to the Error Amplifier. Converter output voltage is offset from the
VDAC voltage through an external resistor connected to the converter output voltage
at the load and an internal current source.
Output of the Error Amplifier
Input to the Regulation Detect Comparator. Connect to converter output voltage and
VDRP pin through resistor network to program recovery from VID step-down.
Connect to ground to disable Body Braking
6.8V/5mA Regulated output used as a system reference voltage for internal circuitry
and the Phase ICs.
Power for internal circuitry
Local Ground and IC substrate connection
Oscillator Output voltage. Used by Phase ICs to program Phase Delay
Controls Converter Softstart, Power Good, and Over-Current Delay Timing. Connect
an external capacitor to LGND to program the timing. An optional resistor can be
added in series with the capacitor to reduce the over-current delay time.
Open Collector output that drives low during Softstart and any external fault
condition. Connect external pull-up.
No internal connection
Enable Input. A logic low applied to this pin puts the IC into Fault mode.
TM
during transition to a lower VID code.
10/01
IR3081
/04