MAX1678EUA Maxim Integrated Products, MAX1678EUA Datasheet - Page 6

• Manufacturer Part Number: MAX1678EUA
• Description: DC/DC Switching Converters
• Manufacturer: Maxim Integrated Products

Specifications of MAX1678EUA

• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

1-Cell to 2-Cell, Low-Noise,
High-Efficiency, Step-Up DC-DC Converter
(Circuit of Figure 7 (Fixed Mode, 3.3V) or Figure 8 (Adjustable Mode), T
6
PIN
_______________________________________________________________________________________
1
2
3
4
5
6
7
8
B
NAME
A
SHDN
A
B
C
BATT
GND
OUT
PFO
V
L1 = SUMIDA CD43-470
A: V
PFI
V
L1 = SUMIDA CD43-470
A: LX, 2V/div
C: INDUCTOR CURRENT, 100mA/div
FB
LX
OUT
OUT
OUT
= 3.3V, V
= 3.3V, V
, 50mV/div, AC COUPLED
LINE-TRANSIENT RESPONSE
SWITCHING WAVEFORM
BATT
Battery-Power Input
Power-Fail Input. When the voltage at PFI is below 614mV, PFO sinks current.
Open-Drain Power-Fail Output. PFO sinks current when PFI is below 614mV.
Active-Low Shutdown. Connect SHDN to BATT for normal operation.
Dual-Mode Feedback Input. Connect FB to GND for fixed-output operation (3.3V). Connect FB to a feed-
back-resistor network for adjustable output voltage operation (2V to 5.5V). FB regulates to 1.23V.
Ground
N-Channel MOSFET Switch Drain and P-Channel Synchronous-Rectifier Drain
Power Output and IC Power Input (bootstrapped). OUT is the feedback input for 3.3V operation. Connect
the filter capacitor close to OUT.
BATT
B: V
= 1.2V, I
= 1.2V, I
OUT
200 s/div
5 s/div
, 50mV/div AC COUPLED
LOAD
LOAD
= 10mA, C
= 10mA, C
B: V
IN
OUT
, 1V/div, 1.2V to 2.2V
OUT
= 10 F,
= 10 F,
Typical Operating Characteristics (continued)
A
= +25°C, unless otherwise noted.)
FUNCTION
A
B
C
C
A
B
V
L1 = SUMIDA CD43-470,
A: V
C: LOAD, 2mA to 12mA
V
L1 = SUMIDA CD43-470
A: V
C: SHDN, 5V/div
OUT
OUT
OUT
OUT
= 3.3V, V
= 3.3V, V
, 1V/div
, 50mV/div, AC COUPLED
LOAD-TRANSIENT RESPONSE
POWER-UP RESPONSE
BATT
BATT
= 1.2V, I
= 1.2V, C
100 s/div
B: INDUCTOR CURRENT, 100mA/div
100 s/div
LOAD
OUT
= 10 F,
= 10mA, C
Pin Description
B: INDUCTOR CURRENT,
100mA/div
OUT
= 10 F,