LM3691_14 Datasheet, PDF (1/23 Pages) Texas Instruments – High Accuracy, Miniature 1A, Step-Down DC-DC Converter for Portable

LM3691
www.ti.com
SNVS506H – MAY 2008 – REVISED SEPTEMBER 2011
LM3691 High Accuracy, Miniature 1A, Step-Down DC-DC Converter for Portable
Applications
Check for Samples: LM3691
FEATURES
1
•2 V_OUT = 0.75V to 3.3V
• ±1% DC Output Voltage Precision
• 2.3V ≤ V_IN ≤ 5.5V
• 4 MHz Switching Frequency
• 64 μA (typ.) Quiescent Current in ECO Mode
• 1A Maximum Load Capability
• Automatic ECO/PWM Mode Switching
• Mode Pin to Select ECO/Forced PWM Mode
• 1 μH Inductor, 4.7 μF Input Capacitor
(0603(1608) case size) and 4.7 μF Output
Capacitor (0603(1608) Case Size)
• Current Overload and Thermal Shutdown
Protections
• Only Three Tiny Surface-mount External
Components Required (Solution Size Less
Than 15 mm²)
DESCRIPTION
The LM3691 step-down DC-DC converter is
optimized for powering ultra-low voltage circuits from
a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It
provides up to 1A load current, over an input voltage
range from 2.3V to 5.5V. There are several different
fixed voltage output options available.
LM3691 has a mode-control pin that allows the user
to select Forced PWM mode or ECO mode that
changes modes between gated PWM mode and
PWM automatically depending on the load. In ECO,
LM3691 offers superior efficiency and very low I_q
under light load conditions. ECO mode extends the
battery life through reduction of the quiescent current
during light load conditions and system standby.
The LM3691 is available in a 6-bump DSBGA
package. Only three external surface-mount
components, a 1 μH inductor, a 4.7 μF input
capacitor and a 4.7 μF output capacitor, are required.
APPLICATIONS
• Mobile Phones
• Hand-Held Radios
• MP3 Players
• Portable Hard Disk Drives
Typical Application Circuit
100
Figure 1. Typical Application Circuit
80
60
V_IN = 2.3V
V_IN = 3.6V
40
V_IN = 4.2V
20
0
0.1
1
10
100
1000
OUTPUT CURRENT (mA)
Figure 2. Efficiency vs. Output Current
(V_OUT = 1.8V, ECO Mode)
1
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2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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