IPS20 ETC2 [List of Unclassifed Manufacturers], IPS20 Datasheet - Page 11

• Manufacturer Part Number: IPS20
• Description: Precision Feedback Controllers Fixed and PTAT references
• Manufacturer: ETC2 [List of Unclassifed Manufacturers]

Power Management IPS20 and IPS21
VSENSE (Pin 2), VCOMP (Pin 3)
The internal voltage reference for voltage feedback is 1.19 volts. The output voltage being sensed/regulated should
have a voltage divider to 1.19 volts connected to pin 2. For good voltage feedback loop performance, no capacitor
should be connected from pin 2 to ground. The recommended series-RC component values from pin 2 to pin 3 to
roll-off the loop gain are 10k ohms and 68nF.
OPTO (Pin 4)
The OPTO pin is a current source (unlike a shunt regulator like the TL431, which is a current sink). The intended
connection for the voltage feedback network is to connect the OPTO pin to the anode of the photodiode in an
optoisolator, with the cathode of the photodiode connected to ground. The IPS20/21 use very little current to operate,
but the user is reminded that the OPTO current being sourced comes through the VCC pin.
ICOMP (Pin 5) and IS (Pin 6)
The current sense resistor connects between IS and GND. For a positive output power supply, IS is the negative
output pin. The internal voltage reference for current limiting (50 millivolts for IPS20, 100 millivolts for IPS21) is
referenced to GND. The recommended component values from pin 5 to pin 6 to roll-off the loop gain are a series 10k
ohms and 220pF, in parallel with 68nF. To reduce susceptability to noise spikes, an additional RC filter network
might be desireable from IS to GND (refer to the Typical Application Schematic Figure 1 above).
OUT(-) (Pin 7)
The negative side of the internal voltage reference for voltage feedback is connected here. For a typical application
with a positive output voltage and a current sense resistor, this pin connects to the more-negative pin of the output
voltage. This configuration allows the voltage feedback to compensate for the voltage drop across the current sense
resistor (which will vary with load).
EVALUATION BOARD
There is an evaluation board (AAEV2021) available for the IPS20 and IPS21 feedback controllers. Contact AAI
Marketing for more details. There are also benchmark/reference designs available that include AAI Flyback
Controllers, and Application Notes.
PACKAGE DIMENSIONS AND MARKING
The IPS20 and IPS21 are available in plastic 8-pin DIP and plastic 8-pin SOIC packages. Refer to the latest version
of specification AAPS001 (ASIC Advantage’s “Package Numbering, Marking, and Outline Standard”, available at
www.asicadvantage.com) for specific information concerning the package dimensions and package marking.
© Copyright 2006-2009 - ASIC Advantage, Inc.
Part Number/Tube
IPS20C-SO-G-LF
IPS21C-SO-G-LF
IPC21I-SO-G-LF
IPS20I-SO-G-LF
IPS20C-D-G-LF
IPS21C-D-G-LF
IPS20I-D-G-LF
IPS21I-D-G-LF
Part Number/Tape&Reel
IPS20C-SO-G-LF-TR
IPS21C-SO-G-LF-TR
IPC21I-SO-G-LF-TR
IPS20I-SO-G-LF-TR
NA
NA
AADS00001/AA743
8-Pin SOIC
8-Pin SOIC
8-Pin PDIP
8-Pin PDIP
Package
- Revision 5– Dec 2008
-40°C to +85°C
-40°C to +85°C
0°C to +70°C
0°C to +70°C
Temperature Range
11 / 12
Commercial
Commercial
Industrial
Industrial