MAX1565ETJ-T Maxim Integrated Products, MAX1565ETJ-T Datasheet - Page 9

• Manufacturer Part Number: MAX1565ETJ-T
• Description: DC/DC Switching Converters 5Ch Digital Camera Power Supply
• Manufacturer: Maxim Integrated Products

(Circuit of Figure 1, T
PIN
1
2
3
4
5
6
7
C OM P S D
COMP1
PGNDA
ONSD
NAME
LXSD
INSD
FB1
0A
0V
STEP-UP LOAD TRANSIENT RESPONSE
_______________________________________________________________________________________
A
= +25°C, unless otherwise noted.)
Auxiliary Controller 1 Compensation Node. Connect a series RC from COMP1 to GND to compensate the
control loop. COMP1 is actively driven to GND in shutdown and thermal limit.
Auxiliary Controller 1 Feedback Input. For 5V output, short FBSEL1 to GND and connect FB1 to the output
voltage. For other output voltages, connect FBSEL1 to OUTSU and connect a resistive voltage-divider from
the step-up converter output to FB1 to GND. The FB1 feedback threshold is then 1.25V. This pin is high
impedance in shutdown.
Power Ground. Connect PGNDA and PGNDB together and to GND with short trace as close to the IC as
possible.
Step-Down Converter Power-Switching Node. Connect LXSD to the step-down converter inductor. LXSD is
the drain of the P-channel switch and N-channel synchronous rectifier. LXSD is high impedance in
shutdown.
Step-Down Converter Input. INSD can connect to OUTSU, effectively making OUTSD a buck-boost output
from the battery. Bypass to GND with a 1µF ceramic capacitor if connected to OUTSU. INSD may also be
connected to the battery, but should not exceed OUTSU by more than a Schottky diode forward voltage.
Bypass INSD with a 10µF ceramic capacitor when connecting to the battery input. A 10kΩ internal
resistance connects OUTSU and INSD.
Step-Down Converter On/Off Control Input. Drive ONSD high to turn on the step-down converter. This pin
has an internal 330kΩ pulldown resistor. ONSD does not start until OUTSU is in regulation.
Step-Down Converter Compensation Node. Connect a series RC from COMPSD to GND to compensate the
control loop. COMPSD is pulled to GND in normal shutdown and during thermal shutdown (see the Step-
Down Compensation section).
400µs/div
Small, High-Efficiency, Five-Channel
Digital Still Camera Power Supply
V
OUTSU
V
IN
MAX1565 toc19
= 3.3V
= 2.5V
Typical Operating Characteristics (continued)
I
200mA/div
V
AC-COUPLED
100mV/div
OUTSU
OUTSU
FUNCTION
0A
0V
STEP-DOWN LOAD TRANSIENT RESPONSE
400µs/div
V
V
OUTSD
OUTSU
V
IN
MAX1565 toc20
= 1.5V
= 3.3V
= 2.5V
Pin Description
I
100mA/div
V
AC-COUPLED
50mV/div
OUTSD
OUTSD
9