Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsPMICsPMIC - DC/DC voltage regulator Holder SOT 23 5

GND

L1:10uH

OUT

10uF

4.7uF

LM3670

2.5V to 5.5V

LM3670

www.ti.com

SNVS250E –NOVEMBER 2004–REVISED FEBRUARY 2013

LM3670 Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits

Check for Samples: LM3670

FEATURES

APPLICATIONS

• V

OUT

= Adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875,

• Mobile Phones

2.5, 3.3V

• HandHeld

• 2.5V ≤ V

≤ 5.5V

• PDAs

• 15 µA Typical Quiescent Current

• Palm-Top PCs

• 350 mA Maximum Load Capability

• Portable Instruments

• 1 MHz PWM Fixed Switching Frequency (typ.)

• Battery Powered Devices

• Automatic PFM/PWM Mode Switching

DESCRIPTION

• Available in Fixed Output Voltages as well as

The LM3670 step-down DC-DC converter is

an Adjustable Version

optimized for powering ultra-low voltage circuits from

• SOT-23-5 Package

a single Li-Ion cell or 3 cell NiMH/NiCd batteries. It

• Low Drop Out Operation - 100% Duty Cycle

provides up to 350 mA load current, over an input

Mode

voltage range from 2.5V to 5.5V. There are several

different fixed voltage output options available as well

• Internal Synchronous Rectification for High

as an adjustable output voltage version.

Efficiency

• Internal Soft Start

The device offers superior features and performance

for mobile phones and similar portable applications

• 0.1 µA Typical Shutdown Current

with complex power management systems. Automatic

• Operates from a Single Li-Ion Cell or 3 Dell

intelligent switching between PWM low-noise and

NiMH/NiCd Batteries

PFM low-current mode offers improved system

• Only Three Tiny Surface-Mount External

control. During full-power operation, a fixed-frequency

1 MHz (typ). PWM mode drives loads from ∼70 mA to

Components Required (One Inductor, Two

350 mA max, with up to 95% efficiency. Hysteretic

Ceramic Capacitors)

PFM mode extends the battery life through reduction

• Current Overload Protection

of the quiescent current to 15 µA (typ) during light

current loads and system standby. Internal

synchronous rectification provides high efficiency (90

to 95% typ. at loads between 1 mA and 100 mA). In

shutdown mode (Enable pin pulled low) the device

turns off and reduces battery consumption to 0.1 µA

(typ.).

Typical Application

Figure 1. Fixed Output Voltage

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2All trademarks are the property of their respective owners.

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.

Summary of content (25 pages)

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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 LM3670 Miniature Step-Down DC-DC Converter for Ultra Low Voltage Circuits Check for Samples: LM3670 FEATURES APPLICATIONS • • • • • • • 1 2 • • • • • • • • • • • • • • VOUT = Adj (0.7V min), 1.2, 1.5, 1.6, 1.8, 1.875, 2.5, 3.3V 2.5V ≤ VIN ≤ 5.5V 15 µA Typical Quiescent Current 350 mA Maximum Load Capability 1 MHz PWM Fixed Switching Frequency (typ.
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LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 www.ti.com DESCRIPTION (CONTINUED) The LM3670 is available in a SOT-23-5 package. A high switching frequency - 1 MHz (typ) - allows use of tiny surface-mount components. Only three external surface-mount components, an inductor and two ceramic capacitors, are required. Typical Application (continued) L1: 4.7 µH or 10 µH[A] VIN 2.5V to 5.5V VIN 1 5 VOUT SW LM3670 CIN: 4.7 µF GND 2 R1 C2 R2 COUT: 10 µF FB EN 3 A.
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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 ORDERING INFORMATION ORDERABLE NUMBER VOLTAGE OPTION (V) LM3670MF-1.2 LM3670MFX-1.2 1.2 LM3670MF-1.2/NOPB LM3670MFX-1.2/NOPB LM3670MF-1.5 LM3670MFX-1.5 1.5 LM3670MF-1.5/NOPB LM3670MFX-1.5/NOPB LM3670MF-1.6 LM3670MFX-1.6 1.6 LM3670MF-1.6/NOPB LM3670MFX-1.6/NOPB LM3670MF-1.8 LM3670MFX-1.8 1.8 LM3670MF-1.8/NOPB LM3670MFX-1.8/NOPB LM3670MF-1.875 LM3670MFX-1.875 1.875 LM3670MF-1.875/NOPB LM3670MFX-1.875/NOPB LM3670MF-2.
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LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 Absolute Maximum Ratings www.ti.com (1) (2) −0.2V to 6.0V VIN Pin: Voltage to GND −0.2V to 6.0V EN Pin: Voltage to GND FB, SW Pin: (GND−0.2V) to (VIN + 0.2V) −45°C to +125°C Junction Temperature (TJ-MAX) −45°C to +150°C Storage Temperature Range Maximum Lead Temperature ESD Rating (Soldering, 10 sec.) 260°C (3) Human Body Model: VIN, SW, FB, EN, GND 2.
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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 Electrical Characteristics Limits in standard typeface are for TJ = 25°C. Limits in boldface type apply over the full operating junction temperature range (−40°C ≤ TJ ≤ +125°C). Unless otherwise noted VIN = 3.6V, VOUT = 1.8V, IO = 150mA, EN = VIN Symbol Parameter VIN Input Voltage Range VOUT Fixed Output Voltage: 1.2V Fixed Output Voltage: 1.5V Fixed Output Voltage: 1.6V, 1.875V Fixed Output Voltage: 1.8V Fixed Output Voltage: 2.
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LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 www.ti.com Electrical Characteristics (continued) Limits in standard typeface are for TJ = 25°C. Limits in boldface type apply over the full operating junction temperature range (−40°C ≤ TJ ≤ +125°C). Unless otherwise noted VIN = 3.6V, VOUT = 1.8V, IO = 150mA, EN = VIN Symbol Parameter Condition IEN Enable (EN) Input Current FOSC Internal Oscillator Frequency PWM Mode Min 550 Typ Max Units 0.
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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 Typical Performance Characteristics (unless otherwise stated: VIN= 3.6V, VOUT= 1.8V) IQ (Non-switching) vs. VIN IQ vs. Temp 0.1 TA = 85°C ISHUTDOWN (PA) NO LOAD IQUIESCENT (PA) 20 TA = 25°C 15 TA = -40°C 10 2.5 3 3.5 4 4.5 5 0.05 0 -40 5.5 -20 0 Figure 5. VOUT vs. VIN VOUT vs. IOUT 1.88 VIN = 3.6V IOUT = 10 mA PFM mode 1.86 1.84 VOUT (V) VOUT (V) IOUT = 150 mA PWM mode 1.79 PFM Mode 1.82 PWM Mode 1.8 1.78 1.
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LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 www.ti.com Typical Performance Characteristics (continued) (unless otherwise stated: VIN= 3.6V, VOUT= 1.8V) RDSON vs. VIN P & N Channel 1010 1000 ILOAD = 150 mA 990 VIN = 3.6V 980 VIN = 5.5V 970 960 950 VIN = 2.5V 940 930 920 910 900 890 880 870 860 850 840 -40 -20 0 10 20 30 40 50 60 70 80 -30 -10 0.8 P FET N FET 0.7 RDSon - N, P CHANNEL (:) FREQUENCY (kHz) Frequency vs. Temperature TA = 85°C TA = 25°C TA = -40°C 0.6 0.5 0.4 0.3 0.2 0.1 2.
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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 Typical Performance Characteristics (continued) (unless otherwise stated: VIN= 3.6V, VOUT= 1.8V) VOUT (50 mV/Div) ILOAD = 280 mA ILOAD = 0 mA Load Transient ILOAD = 0mA to 350mA CURRENT LOAD STEP (0 mA - 350 mA) CURRENT LOAD STEP (0 mA - 280 mA) Load Transient ILOAD = 0mA to 280mA VOUT (50 mV/Div) ILOAD = 350 mA ILOAD = 0 mA TIME (100 Ps/DIV) Figure 17. Figure 18.
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LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 www.ti.com Typical Performance Characteristics (continued) (unless otherwise stated: VIN= 3.6V, VOUT= 1.8V) CURRENT LOAD STEP (3 mA - 280 mA) Soft Start VIN, VOUT, IINDUCTOR vs. Time (ILOAD = 350mA) VIN (2V/Div) VOUT (1V/Div) Inductor Current (200 mA/ Div) TIME (100 Ps/DIV) Figure 23.
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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 OPERATION DESCRIPTION Device Information The LM3670, a high efficiency step down DC-DC switching buck converter, delivers a constant voltage from either a single Li-Ion or three cell NiMH/NiCd battery to portable devices such as cell phones and PDAs.
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LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 www.ti.com PFM Operation At very light load, the converter enters PFM mode and operates with reduced switching frequency and supply current to maintain high efficiency. The part automatically transition into PFM mode when either of two conditions occurs for a duration of 32 or more clock cycles: A. The inductor current becomes discontinuous B.
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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 Soft-Start The LM3670 has a soft-start circuit that limits in-rush current during start-up. Typical start-up times with a 10µF output capacitor and 350mA load is 400µs: Inrush Current (mA) Duration (µSec) 0 32 70 224 140 256 280 256 620 until soft start ends LDO - Low Drop Out Operation The LM3670 can operate at 100% duty cycle (no switching, PMOS switch is completely on) for low drop out support of the output voltage.
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LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 www.ti.com A pole can also be used at higher output voltages. For example, in Table 3, there is an entry for 1.24V with both a pole and zero at approximately 10kHz for noise rejection. Inductor Selection There are two main considerations when choosing an inductor; the inductor current should not saturate, and the inductor current ripple is small enough to achieve the desired output voltage ripple.
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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 Table 1.
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LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 www.ti.com Table 3. Adjustable LM3670 Configurations for Various VOUT (1) VOUT (V) R1 (KΩ) R2 (KΩ) C1 (pF) C2 (pF) L (µH) CIN (µF) COUT (µF) 0.7 80.6 200 200 150 4.7 4.7 10 0.8 120 200 130 none 4.7 4.7 10 0.9 160 200 100 none 4.7 4.7 10 1.0 200 200 82 none 4.7 4.7 10 1.1 240 200 68 none 4.7 4.7 10 1.2 280 200 56 none 4.7 4.7 10 1.24 300 200 56 none 4.7 4.7 10 1.
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LM3670 www.ti.com SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 Good layout for the LM3670 can be implemented by following a few simple design rules, as illustrated in Figure 25. • Place the LM3670, inductor and filter capacitors close together and make the traces short. The traces between these components carry relatively high switching currents and act as antennas. Following this rule reduces radiated noise. Place the capacitors and inductor within 0.2 in. (5 mm) of the LM3670.
PAGE 18
LM3670 SNVS250E – NOVEMBER 2004 – REVISED FEBRUARY 2013 www.ti.com REVISION HISTORY Changes from Revision D (February 2013) to Revision E • 18 Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.com 1-Nov-2013 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan Lead/Ball Finish MSL Peak Temp (2) (6) (3) Op Temp (°C) Device Marking (4/5) LM3670MF-1.2/NOPB ACTIVE SOT-23 DBV 5 1000 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 SCZB LM3670MF-1.5/NOPB ACTIVE SOT-23 DBV 5 1000 Green (RoHS & no Sb/Br) CU SN Level-1-260C-UNLIM -40 to 85 S82B LM3670MF-1.
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PACKAGE OPTION ADDENDUM www.ti.com 1-Nov-2013 (2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined.
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PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) LM3670MF-1.2/NOPB SOT-23 DBV 5 1000 178.0 8.4 LM3670MF-1.5/NOPB SOT-23 DBV 5 1000 178.0 LM3670MF-1.6/NOPB SOT-23 DBV 5 1000 178.0 LM3670MF-1.8 SOT-23 DBV 5 1000 LM3670MF-1.8/NOPB SOT-23 DBV 5 LM3670MF-1.875/NOPB SOT-23 DBV LM3670MF-3.
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PACKAGE MATERIALS INFORMATION www.ti.com 23-Sep-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM3670MF-1.2/NOPB SOT-23 DBV 5 1000 210.0 185.0 35.0 LM3670MF-1.5/NOPB SOT-23 DBV 5 1000 210.0 185.0 35.0 LM3670MF-1.6/NOPB SOT-23 DBV 5 1000 210.0 185.0 35.0 LM3670MF-1.8 SOT-23 DBV 5 1000 210.0 185.0 35.0 LM3670MF-1.8/NOPB SOT-23 DBV 5 1000 210.0 185.0 35.0 LM3670MF-1.
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