MAX1700 Maxim, MAX1700 Datasheet - Page 8

• Manufacturer Part Number: MAX1700
• Description: 1-Cell to 3-Cell / High-Power 1A / Low-Noise / Step-Up DC-DC Converters
• Manufacturer: Maxim

1-Cell to 3-Cell, High-Power (1A),
Low-Noise, Step-Up DC-DC Converters
8
MAX1700
1, 2, 6, 9,
10, 16
_______________________________________________________________________________________
11
12
13
14
15
—
—
—
—
—
—
3
4
5
7
8
PIN
MAX1701
10
11
12
13
14
15
16
—
1
2
3
4
5
6
7
8
9
CLK/SEL
NAME
PGND
POUT
GND
ONB
ONA
POK
OUT
LBO
LBN
LBP
REF
AIN
I.C.
AO
FB
LX
Low-Battery Comparator Non-Inverting Input
Low-Battery Comparator Inverting Input
Reference Output. Bypass with a 0.22µF capacitor to GND. REF can source up to
50µA.
Switching-Mode Selection and External-Clock Synchronization Inputs.
• CLK/SEL=Low: Low-power, delivers up to 10% of full load current.
• CLK/SEL=High: High-power PWM mode. Full output power available. Operates in
• CLK/SEL=External Clock: High-power PWM mode with the internal oscillator
Turning on with CLK/SEL=0V also serves as a soft-start function since peak inductor
current is limited to 25% of that allowed in PWM mode.
Ground
Power-Okay Comparator Output. Open drain N-channel output is low when V
10% below regulation point. No internal delay is provided.
Shutdown Input. When ONB =high and ONA=low, the IC is off and the load is connect-
ed to the battery through the Schottky diode.
Turn ON Input. When ONA=high or ONB =low, the IC turns on.
Gain Block Output. This open-drain output sinks when V
Gain Block AIN input. When AIN is low, AO sinks current. The transconductance from
AIN to AO is 9mmhos.
DC-DC Converter Dual-Mode Feedback Input. For a fixed output voltage of +3.3V,
connect FB to GND. For adjustable output, connect a divider between POUT and GND
to set the output voltage in the range of 2.5V to 5V.
Source of N-Channel Power MOSFET Switch. Connect to high-current ground path.
Drain of P-Channel Synchronous Rectifier and N-Channel Switch
Output Sense Input. Power source for the IC.
Source of P-Channel Synchronous Rectifier MOSFET Switch. Connect an external
Schottky diode from LX to POUT.
Low-Battery Comparator Output. Open-drain N-channel output is low when LBN > LBP
Input hysteresis is 15mV.
Internal Connection. Leave open or connect to GND.
low-noise, constant-frequency mode.
synchronized to the external clock.
FUNCTION
AIN
<V
Pin Description
REF
.
OUT
is