Intersil ISL62381, Руководство пользователя

Страница: 2 / 13

2
AN1396.0
July 31, 2008
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: R
eplace C
6
(C
25
for Channel 2) with R
OCSET;
Step 5: R
eplace replace R
19
(R
18
for Channel 2) with
R
OCSET.
Dynamic Load Generator
The evaluation board provides each PWM channel an
on-board dynamic load generator for evaluating the
transient-load response, which are controlled by SW1 and
SW2 respectively. The dynamic load generator applies a
300µs pulse load across V
OUT
and GND. The transient load
slew-rate can be trimmed by adjusting the resistors R
34
, R
40
for the rising edge, and R
38
, R
39
for the falling edge. +12V
power supply is needed to power the dynamic load
generator.
Connections and Test Points
The following table describes the function and operation of the evaluation boards.
NUMBER NAME FUNCTION/OPERATION
INTERFACES AND CONNECTIONS
TP3 VBAT V
IN
positive power input
TP4 GND V
IN
return power input
TP1 VOUT1 Channel-1 positive power output
TP2 GND Channel-1 return power output
TP11 VOUT2 Channel-2 positive power output
TP12 GND Channel-2 return power output
TP20 +12V +12V positive power input, used for the power supply of the on-board dynamic-load generator
TP19 GND +12V return power input
TEST POINTS
J1 PHASE2 Scope-probe socket for measuring Channel-2 phase node
J3 PHASE1 Scope-probe socket for measuring Channel-1 phase node
J2 VOUT1 Scope-probe socket for measuring Channel-1 output
J5 VOUT2 Scope-probe socket for measuring Channel-2 output
J4 FLOAT_FCCM Remove the jumper will float the FCCM pin
J6 FLOAT_EN1 Remove the jumper will float the EN1 pin
J7 FLOAT_EN2 Remove the jumper will float the EN2 pin
TP17 EN1 Test point of EN1 pin
TP8 EN2 Test point of EN2 pin
TP9 LDO3EN Test point of LDO3EN pin
TP10 FCCM Test point of FCCM pin
POWER-GOOD INDICATORS
TP13 PGOOD1 Test point of PGOOD1 pin
TP5 PGOOD2 Test point of PGOOD2 pin
D1 Channel-1 Power-Good indicator. Green when VOUT1 is in regulation.
D2 Channel-2 Power-Good indicator. Green when VOUT2 is in regulation.
LINEAR REGULATORS
TP14 LDO5 LDO5 linear regulator positive power output
TP15 GND LDO5 linear regulator return power output
TP16 LDO3IN Input of LDO3 linear regulator. Connect to connected to a voltage greater than the LDO3 set point plus the dropout
voltage.
TP18 LDO3FB LDO3 linear regulator output voltage feedback test point
TP6 LDO3 LDO3 linear regulator positive power output
TP7 GND LDO3 linear regulator return power output
Application Note 1396