ST ISA067V1 User Manual

STEVAL-ISA067V1
Dual step-down controller with auxiliary voltages demonstration
board based on the PM6681A for industrial system power
5.5 V to 36 V input voltage range
V
V
0.9 - 3.3 V adjustable LDO delivers 100 mA
5 V LDO delivers 100 mA peak current
1.237 V ± 1% reference voltage available
Loss-less current sensing using low-side
Soft-start internally fixed at 2 ms
Soft output discharge
Latched UVP
Non-latched OVP
Selectable pulse-skipping at light loads
Selectable minimum frequency (33 kHz) in
4 mW maximum quiescent power
Independent power-good signals
Output voltage ripple compensation
RoHS compliant
out1
: 3.3 V, I
> 2.5 A (or adjustable output
out1
voltage)
out2
: 1.8 V, I
> 2.5 A (or adjustable output
out2
voltage)
peak current
MOSFET R
DS(on)
Negative current limit
pulse-skip mode
STEVAL-ISA067V1
respectively. Each switching section delivers more than 2.5 A output current.
An internal linear regulator provides a fixed 5 V output voltage. Another internal linear regulator provides an adjustable output voltage (default 2.5 V). Both linear regulators can deliver up to 100 mA peak current.
Data brief
Description
This demonstration board is based on the PM6681A, a dual step-down controller with adjustable output voltages that can be used in industrial power systems. The PM6681A demonstration board allows testing all the device's functions and provides two switching sections, with (typically) 3.3 V (OUT1) and 1.8 V (OUT2) outputs from 5.5 V to 36 V input voltage.
The typical operating switching frequency of the two available sections is 200 kHz/300 kHz,
April 2009 Doc ID 15643 Rev 1 1/4
For further information contact your local STMicroelectronics sales office.
www.st.com
4
Circuit schematic STEVAL-ISA067V1

1 Circuit schematic

Figure 1. Schematic diagram

2/4 Doc ID 15643 Rev 1
AM01437v1
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