MAX1709ESE Maxim Integrated Products, MAX1709ESE Datasheet - Page 8

• Manufacturer Part Number: MAX1709ESE
• Description: IC DC/DC CONV STEP-UP 4A 16-SOIC
• Manufacturer: Maxim Integrated Products
• Type: Step-Up (Boost)r

Specifications of MAX1709ESE

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 3.3V, 5V, Adj
• Current - Output: 4A
• Frequency - Switching: 600kHz
• Voltage - Input: 0.7 ~ 5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Power - Output: 1.3W
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: Q1226679

4A, Low-Noise, High-Frequency,
Step-Up DC-DC Converter
The MAX1709 step-up converter offers high efficiency
and high integration for high-power applications. It
operates with an input voltage as low as 0.7V and is
suitable for single- to 3-cell battery inputs as well as
2.5V or 3.3V regulated supply inputs. The output volt-
age is preset to +3.3V or +5.0V or can be adjusted with
external resistors for voltages between +2.5V to +5.5V.
The n-channel switch of the MAX1709EUI+ is rated for
10A
input and output voltage. The n-channel switch of the
MAX1709ESE has a 6A
2.4A output. The MAX1709ESE has a lower RMS switch
rating than the MAX1709EUI+, but has the same peak
switch current limit and so can supply 4A loads inter-
mittently. For flexibility, the current limit and soft-start
rate are independently programmable.
A 600kHz switching frequency allows for a small induc-
tor to be used. The switching frequency is also syn-
chronizable to an external clock ranging from 350kHz
to 1000kHz.
Figure 1. Standard Operating Circuit
8
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RMS
and can deliver loads up to 4A, depending on
Detailed Description
SHORT AND WIDE
RMS
KEEP TRACES
R1
CONTROL
rating and supplies up to
ON-OFF
C3
C4
0.22μF
ONA
LX
LX
LX
GND
SS/LIM
REF
GND
MAX1709
1μH
D1
L1
The logic levels at ONA and ONB turn the MAX1709 on
or off. When ONA = 1 or ONB = 0, the part is on. When
ONA = 0 and ONB = 1, the part is off (Table 1). Logic-
high on control can be implemented by tying ONB high
and using ONA for shutdown. Implement inverted sin-
gle-line on/off control by grounding ONA and toggling
ONB. Implement momentary pushbutton On/Off as
described in the Applications Information section. Both
inputs have approximately 0.15V of hysteresis.
The MAX1709 switches at the fixed-frequency internal
oscillator rate (600kHz) or can be synchronized to an
external clock. Connect CLK to OUT for internal clock
operation. Apply a clock signal to CLK to synchronize
to an external clock. The frequency can be changed on
the fly. The MAX1709 will synchronize to a new external
clock rate in two cycles and will take approximately
40µs to revert to its internal clock frequency once the
external clock pulses stop and CLK is driven high.
Table 2 summarizes oscillator operation.
PGND
PGND
PGND
3.3/5
ONB
OUT
CLK
FB
C5
0.1μF
C6, C7
2 x
150μF
2Ω
R2
C1, C2
2 x 150μF
Switching Frequency
GND
V
1V TO 5V
V
5V
IN
OUT
ONA, ONB