MAX1677EEE Maxim Integrated Products, MAX1677EEE Datasheet - Page 9

• Manufacturer Part Number: MAX1677EEE
• Description: IC CONV DC-DC STEP-UP 16-QSOP
• Manufacturer: Maxim Integrated Products
• Type: Step-Up (Boost)r

Specifications of MAX1677EEE

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 2
• Voltage - Output: 3.3V or Adj Main, -28 ~ 28 V or Adj Secondary
• Current - Output: 350mA
• Frequency - Switching: 300kHz
• Voltage - Input: 0.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-QSOP
• Power - Output: 696mW
• Output Voltage: 2.5 V to 5.5 V
• Output Current: 350 mA
• Input Voltage: 0.7 V to 5.5 V
• Supply Current: 35 uA
• Switching Frequency: 300 KHz
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Figure 1. Functional Block Diagram
Table 1. Main Boost Converter Available
Output Current
1 Alk/NiCd/NiMH
1 Alk/NiCd/NiMH
2 Alk/NiCd/NiMH
2 Alk/NiCd/NiMH
1 Alk/NiCd/NiMH
or 1 Li-Ion
LCDPOL
NUMBER OF
LCDFB
GND
REF
CELLS
ON
MAX1677
_______________________________________________________________________________________
VOLTAGE
Step-Up and LCD Bias DC-DC Converter
ISET/POL SENSE
ON
IN
REFERENCE
INPUT
Compact, High-Efficiency, Dual-Output
1.2
1.2
2.4
2.4
3.6
(V)
I
LCDLX
POL
REF
STARTUP OSC
ON
VOLTAGE
OUTPUT
MBC
OUT
3.3
3.3
(V)
5
5
5
2.25V
MBC OUTPUT
CURRENT
PWM/PFM
140/150
350/170
260/125
350/170
100/70
501k
(mA)
START-UP
839k
ST
EA
I
90% REF
LCDLX
The MBC operates either in PFM mode, 300kHz PWM
mode, or externally synchronized PWM mode as select-
ed by the CLK/SEL input (Table 2). PWM mode offers
fixed-frequency operation and maximum output power.
PFM mode offers the lowest IC operating current. LX
current limit is reduced in PFM mode to increase effi-
ciency and minimize output ripple.
When CLK/SEL is high, the MAX1677 operates in its
high-power, low-noise PWM mode, switching at the
300kHz internal oscillator frequency. The MOSFET
switch pulse-width is modulated to control the power
transferred on each switching cycle and regulate the
CL
LCD ON
POL
LCD BIAS
LCDDRV
ON
MAIN DC-DC
SUCLK
EA
Main Boost Converter (MBC)
CLK
ON
50% REF
QN
QP
PWM Mode
OUT
CLK/SEL
POUT
LX
FB
LBO
LBI
LCDON
LCDLX
LCDGND
PGND
9