Datasheet

EVAL-ADP1655
Rev. 0 | Page 10 of 20
DAUGHTERBOARD
ADP1655 EVAL BOARD
2.65 – 5.5V
CONNECT DC
SUPPLY WITH
SHORT CABLES
MEASURE I
HPLED
WITH
CURRENT LOOP
CLOSE J9
FOR 1 LED
E
VALUATION
MEASURE INDUCTOR CURRENT
WITH CURRENT LOOP
MEASURE SUPPLY CURRENT
WITH CURRENT LOOP
ADP1655
08032-016
Figure 14. Daughterboard
The ADP1655 evaluation daughterboard is designed to quickly
evaluate key parameters of the ADP1655 IC. The board layout
footprint is extended so that parts can be exchanged and
headers are available to measure currents using a current probe
or ammeter.
Connect a power supply or Li-Ion battery with 2 A capability to
VIC. Up to 1.8 A can be drawn from the battery; therefore,
short, thick cables are recommended to minimize the IR drops.
A high current can cause a big IR drop, and V
IN
of ADP1655 can be
low enough to put the part into UVLO.
REMOVE R7, R9, AND R13 FOR
SHUTDOWN AND STANDBY
CURRENT EVALUATION
LIFT UP PIN 1 AND PIN 8 OF U20
AND U22 FOR SHUTDOWN AND
STANDBY CURRENT EVALUATION
ADP1655 DAUGHTERBOARD BOTTOM SIDE
08032-017
Figure 15. Daughterboard Modifications for ADP1655 Shutdown and
Standby Current Measurement.
I
Q
I
Q
is the supply current and can be measured by using an
ammeter across J7. On the bottom side of the ADP1655
daughterboard, Resistor R7, Resistor R9, and Resistor R13, as
well as IC U20 and IC U22, are connected to the supply voltage,
which affect I
Q
measurement. Follow the instructions described
in Figure 15 for ADP1655 shutdown and standby mode current
measurements.
I
L
I
L
is the inductor current and can be measured by using a current
loop across J13.
I
LED
I
LED
is the LED current and can be measured by using an
ammeter or current loop across J8.
High V
F
LEDs
By default, R1 is 0.1 Ω. It can be replaced with another resistor
for current measurement or for increasing the LED_OUT
voltage (to simulate a higher boost ratio for a high V
F
LED).