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ISL62386LOEVAL1Z and ISL62386HIEVAL1Z
Quad-Output Evaluation Board User Guide
Introduction
The ISL62386 evaluation boards demonstrates the
performance of the ISL62386 quad-output voltage controller.
The ISL62386 includes two pulse-width modulated (PWM)
controllers featuring Intersil’s patented R
3
technology and
two linear regulators, LDO5 and LDO3. The PWM controllers
are adjustable from 0.6V to 5.5V, and the LDOs generate
fixed 5V and 3.3V outputs respectively.
The evaluation board includes independent Enable
switches, one LED Power-Good indicator and numerous test
points. Included with each switching channel is an on-board
dynamic load generator for evaluating the transient-load
response. There are two variations of the evaluation boards
to provide flexible evaluation options. Table 1 shows a brief
description of the evaluation boards.
What’s Needed
The following materials will be needed to perform testing:
• Adjustable +25V, 30A Power Supply
• +12V, 100mA Power Supply
• Precision digital multi-meter
• 4 Electronic Loads
• 4-Channel Oscilloscope
Enable Control
The evaluation board provides flexible control logic to enable
or disable the outputs, and to program the two PWM
channels’ start-up sequence. Table 2 is the enable controller
truth table. For start-up timing sequence, please refer to the
datasheet waveforms.
.
Resistor Current Sense Configuration
The evaluation board is pre-configured with inductor DCR
current sense. For more precise overcurrent protection, it
also provides the option of resistor current sense. Figure 1
shows the configuration for resistor current sense.
For Channel-1, the ISL62386 monitors the OCSET1 pin and
the ISEN1 pin voltages. Once the OCSET1 pin voltage is
higher than the ISEN1 pin voltage for more than 10µs, the
ISL62386 declares an overcurrent fault. For a chosen
overcurrent set point I
OC
and current sense resistor R
SENSE
,
the value of R
OCSET
is determined by Equation 1
Where:
-R
OCSET
(Ω) is the resistor used to program the
overcurrent setpoint
-I
OC
is the output current threshold that will activate the
OCP circuit
-R
SENSE
is current sense resistor (R
3
for Channel-1 and
R
25
for Channel-2)
Take Channel-1 as an example, once the value of R
OCSET
is calculated, follow the following procedure to configure the
resistor current sense circuit:
Step 1: Open the “DCR SENSE” solder bridge and
connect the “RESISTOR SENSE” solder bridge
on the PCB bottom layer;
Step 2: Remove R
7
(R
22
for Channel-2);
Step 3: Replace R
3
(R
25
for Channel-2) with R
SENSE
;
Step 4: Replace C
6
(C
25
for Channel-2) with R
OCSET;
Step 5: Replace R
19
(R
18
for Channel-2) with R
OCSET.
TABLE 1. EVALUATION BOARD DESCRIPTION
EVALUATION BOARD CHANNEL-1 CHANNEL-2 OCP
ISL62386LOEVAL1Z 3.3V/8A 5V/8A ~10A
ISL62386HIEVAL1Z 1.05V/15A 1.5V/15A ~20A
TABLE 2. ENABLE TRUTH TABLE
EN1 EN2 START-UP SEQUENCE
Low Low Both Channel outputs OFF simultaneously
Low Float Both Channel outputs OFF simultaneously
Float Low Both Channel outputs OFF simultaneously
Float Float Both Channel outputs OFF simultaneously
Low High Channel-1 OFF, Channel-2 ON
High Low Channel-1 ON, Channel-2 OFF
High High Both Channel outputs ON simultaneously
Float High Channel-1 enabled after Channel-2 is in regulation
High Float Channel-2 enabled after Channel-1 is in regulation
TABLE 2. ENABLE TRUTH TABLE (Continued)
EN1 EN2 START-UP SEQUENCE
FIGURE 1. RESISTOR CURRENT SENSE CIRCUIT
PHASEx
C
O
L
V
O
OCSETx
ISENx
R
O
ISL62386
I
L
10µA
+
_
V
RSENSE
+
V
ROCSET
_
R
SENSE
R
OCSET
(EQ. 1)
R
OCSET
I
OC
R
SENSE
•
10μA
-------------------------------------
=
August 25, 2009 AN1456.0Application Note
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
1-888-INTERSIL or 1-888-468-3774
| Intersil (and design) is a registered trademark of Intersil Americas Inc.
Copyright Intersil Americas Inc. 2009. All Rights Reserved
All other trademarks mentioned are the property of their respective owners.
