Renesas ISL85003EVAL2Z User Manual

ISL85003EVAL2Z, ISL85003AEVAL2Z
Evaluation Board User Guide
Description
The ISL85003 and ISL85003A kits are intended for use for
point-of-load applications sourcing from 4.5V to 18V. The kits
are used to demonstrate the performance of the ISL85003
and ISL85003A, low quiescent current high efficiency
synchronous buck regulators.
The ISL85003 and ISL85003A are offered in a 4x3mm dual flat
no lead (DFN) package.

Specifications

The boards are designed to operate at the following operating
conditions:
• Input voltage range from 4.5V to 18V
• Resistor programmable output voltage from 0.8V,
• Up to 3A output current
• Current mode control
- DCM/CCM
- Internal or external compensation options
- 500kHz switching frequency option
- External synchronization up to 2MHz on ISL85003
• Adjustable soft-start time on the ISL85003A
• Operating junction temperature range: -40°C to +125°C

Quick Setup Guide

1. Ensure that the circuit is correctly connected to the supply
and loads prior to applying any power.
2. Connect the bias supply to VIN, the plus terminal to VIN (P4)
and the negative return to PGND (P5).
3. Connect the output load to V0, the plus terminal to V0 (P8)
and the negative return to PGND (P9).
4. Verify that the position is PWM or PFM for SW2.
5. Verify that the position is ON for SW1.
6. Turn on the power supply.
7. Verify the output voltage is 5V for VO.
Recommended Equipment
The following materials are recommended to perform testing:
• 0V to 25V power supply with at least 10A source current
capability
• Electronic loads capable of sinking current up to 7A
• Digital multimeters (DMMs)
• 100MHz quad-trace oscilloscope
• Signal generator
AN1930 Rev.1.00
Aug 28, 2014
Key Board Features
• Small, compact design
• Switch selectable EN (enabled/disabled)
• Switch selectable MODE (auto-DCM/forced-PWM)
• Connectors and test points for easy probing
References
• ISL85003,

Ordering Information

PART NUMBER
1%
±
ISL85003EVAL2Z
Evaluating the Other Output
Voltage
The ISL85003 and ISL85003A kit outputs are preset to 5V for
V ; however, the output voltages are programmed using an
OUT
external resistor divider that scales the feedback relative to the
internal reference voltage. The output voltage programming
resistor, R
2
resistor, R
1
The value for the feedback resistor R
10kΩ and 400kΩ as shown in

R
1
------------------------------ -
R =
2
V
OUT
If the output voltage desired is 0.8V, then R
unpopulated. R
of the modulator compensation.
Switch Control
The ISL85003 and ISL85003A evaluation boards contain SW1
and SW2 for various controls of the ISL85003 and ISL85003A
circuitries.
SW1
1
3
SW2
1
3
USER'S MANUAL
ISL85003A datasheet
DESCRIPTION
Evaluation Board for ISL85003FRZ and
ISL85003AFRZ
, will depend on the value chosen for the feedback
, and the desired regulator output voltage, V
is typically between
1
Equation 1.
0.8V
– 0.8V
is still required to set the low frequency pole
1
Table 1 details this function.
TABLE 1. SWITCH SETTINGS
ENABLE FUNCTION
OFF Disable V0
ON Enable V0
MODE FUNCTION
DCM Force DCM
PWM Fixed PWM frequency at light load
AN1930
Rev.1.00
Aug 28, 2014
.
OUT
(EQ. 1)
is left
2
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