LM3671MF-3.3

Part: LM3671, LM3671Q — Texas Instruments

Type: Step-Down DC-DC Converter

Description: A 2.7–5.5V input, 600mA step-down DC-DC converter with 2 MHz switching frequency, automatic PFM/PWM mode switching, and fixed/adjustable output voltage options from 1.1V to 3.3V.

Operating Conditions:

• Supply voltage: 2.7V to 5.5V
• Operating temperature: -40°C to +125°C (Junction)
• Recommended load current: 0mA to 600 mA
• PWM switching frequency: 2 MHz (typ.)

Absolute Maximum Ratings:

• Max supply voltage: 6.0V
• Max junction temperature: +125°C
• Storage temperature: -65°C to +150°C

Key Specs:

• Quiescent Current (I Q): 16 μA (typ.), 35 μA (max) (No load, not switching)
• Shutdown Supply Current (I SHDN): 0.01 μA (typ.), 1 μA (max) (EN = 0V)
• PFET On-Resistance (R DSON (P)): 380 mΩ (typ.), 500 mΩ (max) (V IN = V GS = 3.6V)
• NFET On-Resistance (R DSON (N)): 250 mΩ (typ.), 400 mΩ (max) (V IN = V GS = 3.6V)
• Switch Peak Current Limit (I LIM): 830 mA (min), 1020 mA (typ), 1150 mA (max) (Open Loop)
• Internal Oscillator Frequency (F OSC): 1.6 MHz (min), 2 MHz (typ), 2.6 MHz (max) (PWM Mode)
• Adjustable Output Voltage Range: 1.1V to 3.3V
• Fixed Output Voltage Options: 1.2V to 3.3V

Features:

• 16 μA Typical Quiescent Current
• 600 mA Maximum Load Capability
• 2 MHz PWM Fixed Switching Frequency (typ.)
• Automatic PFM/PWM Mode Switching
• Internal Synchronous Rectification for High Efficiency
• Internal Soft start
• 0.01 μA Typical Shutdown Current
• Operates from a Single Li-Ion Cell Battery
• Only Three Tiny Surface-Mount External Components Required (One Inductor, Two Ceramic Capacitors)
• Current Overload and Thermal Shutdown Protection
• Available in Fixed Output Voltages and Adjustable Version
• LM3671Q is an Automotive Grade Product that is AEC-Q100 Grade 1 Qualified

Applications:

• Mobile Phones
• PDAs
• MP3 Players
• W-LAN
• Portable Instruments
• Digital Still Cameras
• Portable Hard Disk Drives
• Automotive

Package:

• SOT-23 (5-pin)
• 5-Bump DSBGA (5-bump)
• 6-Pin USON (6-pin)

• 2 · 16 μA Typical Quiescent Current
• 600 mA Maximum Load Capability
• 2 MHz PWM Fixed Switching Frequency (typ.)
• Automatic PFM/PWM Mode Switching
• Internal Synchronous Rectification for High Efficiency
• Internal Soft start
• 0.01 μA Typical Shutdown Current
• Operates from a Single Li-Ion Cell Battery
• Only Three Tiny Surface-Mount External Components Required (One Inductor, Two Ceramic Capacitors)
• Current Overload and Thermal Shutdown Protection
• Available in Fixed Output Voltages and Adjustable Version
• LM3671Q is an Automotive Grade Product that is AEC-Q100 Grade 1 Qualified
• SOT-23, 5-Bump DSBGA and 6-Pin USON Packages

• Mobile Phones
• PDAs
• MP3 Players
• W-LAN
• Portable Instruments
• Digital Still Cameras
• Portable Hard Disk Drives
• Automotive

Limits in standard typeface are for T J = 25°C. Limits in boldface type apply over the entire junction temperature range for operation, -40°C to +125°C. Unless otherwise noted, specifications apply to the LM3671MF/TL/LC with VIN = EN = 3.6V

• (4) The input voltage range recommended for ideal applications performance for the specified output voltages are given below:VIN = 2.7V to 4.5V for 1.1V ≤ VOUT < 1.5VVIN = 2.7V to 5.5V for 1.5V ≤ VOUT < 1.8VVIN = (VOUT+ VDROPOUT) to 5.5V for 1.8V ≤ VOUT ≤ 3.3Vwhere VDROPOUT = ILOAD *( RDSON, PFET + RINDUCTOR)
• (5) Test condition: for V OUT less than 2.5V, V IN = 3.6V; for V OUT greater than or equal to 2.5V, V IN = VOUT+ 1V.
• (6) ADJ version is configured to 1.5V output. For ADJ output version: V IN = 2.7V to 4.5V for 0.90V ≤ VOUT < 1.1VVIN = 2.7V to 5.5V for 1.1V ≤ VOUT < 3.3V

(7) Refer to datasheet curves for closed loop data and its variation with regards to supply voltage and temperature. Electrical Characteristic table reflects open loop data (FB=0V and current drawn from SW pin ramped up until cycle by cycle current limit is activated). Closed loop current limit is the peak inductor current measured in the application circuit by increasing output current until output voltage drops by 10%.

• (1) Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings are conditions under which operation of the device is specified. Operating Ratings do not imply specified performance limits. For specified performance limits and associated test conditions, see the Electrical Characteristics tables.
• (2) If Military/Aerospace specified devices are required, please contact the Texas Instruments Sales Office / Distributors for availability and specifications.
• (3) Internal thermal shutdown circuitry protects the device from permanent damage. Thermal shutdown engages at TJ= 150°C (typ.) and disengages at TJ= 130°C (typ.).
• (4) The Human body model is a 100 pF capacitor discharged through a 1.5 k Ω resistor into each pin. The machine model is a 200 pF capacitor discharged directly into each pin. MIL-STD-883 3015.7

• (1) Junction to ambient thermal resistance is highly application and board layout dependent. In applications where high power dissipation exists, special care must be given to thermal dissipation issues in board design. Specified value of 130 °C/W for SOT-23 is based on a 4 layer, 4" x 3", 2/1/1/2 oz. Cu board as per JEDEC standards is used.

Figure 1. Typical Application Circuit

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