ISL62386LOEVAL1Z データシートの表示（PDF） - Intersil
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ISL62386LOEVAL1Z
Intersil
ISL62386LOEVAL1Z Datasheet PDF : 13 Pages
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ISL62386LOEVAL1Z and ISL62386HIEVAL1Z
®
Quad-Output Evaluation Board User Guide
Application Note
August 25, 2009
AN1456.0
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 R3 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.
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
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.
.
EN1
Low
Low
Float
Float
Low
High
High
TABLE 2. ENABLE TRUTH TABLE
EN2
START-UP SEQUENCE
Low Both Channel outputs OFF simultaneously
Float Both Channel outputs OFF simultaneously
Low Both Channel outputs OFF simultaneously
Float Both Channel outputs OFF simultaneously
High Channel-1 OFF, Channel-2 ON
Low Channel-1 ON, Channel-2 OFF
High Both Channel outputs ON simultaneously
TABLE 2. ENABLE TRUTH TABLE (Continued)
EN1 EN2
START-UP SEQUENCE
Float High Channel-1 enabled after Channel-2 is in regulation
High Float Channel-2 enabled after Channel-1 is in regulation
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.
PHASEx
L
RSENSE IL
VO
+
_
VRSENSE
ISL62386
CO
10µA
OCSETx
ROCSET
_
+
VROCSET
RO
ISENx
FIGURE 1. RESISTOR CURRENT SENSE CIRCUIT
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 IOC and current sense resistor RSENSE,
the value of ROCSET is determined by Equation 1
ROCSET
=
I--O-----C-----•--R-----S----E----N----S----E--
10 μ A
(EQ. 1)
Where:
- ROCSET (Ω) is the resistor used to program the
overcurrent setpoint
- IOC is the output current threshold that will activate the
OCP circuit
- RSENSE is current sense resistor (R3 for Channel-1 and
R25 for Channel-2)
Take Channel-1 as an example, once the value of ROCSET
is calculated, follow the following procedure to configure the
resistor current sense circuit:
Step 1:
Step 2:
Step 3:
Step 4:
Step 5:
Open the “DCR SENSE” solder bridge and
connect the “RESISTOR SENSE” solder bridge
on the PCB bottom layer;
Remove R7 (R22 for Channel-2);
Replace R3 (R25 for Channel-2) with RSENSE;
Replace C6 (C25 for Channel-2) with ROCSET;
Replace R19 (R18 for Channel-2) with ROCSET.
1
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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Copyright Intersil Americas Inc. 2009. All Rights Reserved
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