LTC4012CUF-3 datasheet, PDF - EEWORLD Datasheet

FeaTures

n

LTC4012-3

High Efficiency,

Multi-Chemistry Battery Charger

with PowerPath Control

DescripTion

The LTC

®

4012-3 is a constant-current/constant-voltage

battery charger controller. It uses a synchronous quasi-

constant frequency PWM control architecture that will not

generate audible noise with ceramic bulk capacitors. Charge

current is set by external resistors and can be monitored

as an output voltage across the programming resistor.

With no built-in termination, the LTC4012-3 charges a

wide range of batteries under external control.

The LTC4012-3 features fully adjustable output voltage. For

charge management and safety, the IC includes an input

P-channel MOSFET ideal diode controller, battery (output)

overvoltage protection, reverse charge current protection,

PWM soft-start and robust non-overlap control for an all

N-channel MOSFET PWM power stage.

The device includes AC adapter input current limiting, which

maximizes the charge rate for a fixed input power level. An

external sense resistor programs the input current limit,

and the

ICL

status pin indicates reduced charge current as

a result of AC adapter current limiting. Ideal diode control

at the adaptor input improves charger efficiency.

The

CHRG

status pin is active during all charging modes,

including special indication for low charge current.

General Purpose Battery Charger Controller

n

Efficient 550kHz Synchronous Buck PWM Topology

n

±0.5% Output Float Voltage Accuracy

n

Programmable Charge Current: 4% Accuracy

n

Programmable AC Adapter Current Limit:

3% Accuracy

n

No Audible Noise with Ceramic Capacitors

n

INFET Low Loss Ideal Diode PowerPath™ Control

n

Wide Input Voltage Range: 6V to 28V

n

Wide Output Voltage Range: 2V to 28V

n

Indicator Outputs for Charging, C/10 Current

Detection and Input Current Limiting

n

Analog Charge Current Monitor

n

Micropower Shutdown

n

20-Pin 4mm

×

4mm

×

0.75mm QFN Package

applicaTions

n

Notebook Computers

Portable Instruments

Battery Backup Systems

L,

LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and

PowerPath and ThinSOT are trademarks of Linear Technology Corporation. All other trademarks

are the property of their respective owners. Protected by U.S. Patents including 5723970.

Typical applicaTion

FROM

ADAPTER

13V TO 20V

INFET

DCIN

0.1µF

CLP

CLN

BOOST

TGATE

SW

INTV

DD

BGATE

GND

CSP

25m

0.1µF

5.1k

20µF

POWER TO

SYSTEM

100

95

0.1µF

EFFICIENCY (%)

90

85

80

75

33m

70

V

OUT

= 12.3V

R

SENSE

= 33m

R

IN

= 3.01k

R

PROG

= 26.7k

0

0.5

1

1.5

2

CHARGE CURRENT (A)

PIN 5 NAME

ACP

X

4012-3 TA02

Efficiency at DCIN = 20V

10000

EFFICIENCY

POWER LOSS (mW)

CHRG

TO/FROM

MCU

ICL

SHDN

ITH

6.04k

0.1µF

PROG

26.7k

4.7nF

POWER LOSS

1000

2µF

6.8µH

3.01k

LTC4012-3

CSN

BAT

FBDIV

V

FB

3.01k

2.5

3

100

301k

32.8k

20µF

+

12.3V

Li-Ion

BATTERY

4012-3 TA01

PART

GND

LTC4012

LTC4012-3

X

40123fb

LTC4012-3

absoluTe MaxiMuM raTings

(Note 1)

pin conFiguraTion

TOP VIEW

INTV

DD

BOOST

BGATE

15 CSP

14 CSN

21

13 PROG

12 ITH

11 BAT

6

SHDN

7

CHRG

8

ICL

9 10

FBDIV

V

FB

TGATE

SW

DCIN ............................................................–14V to 30V

DCIN to CLP ................................................ –32V to 20V

CLP, CLN or SW to GND............................. –0.3V to 30V

CLP to CLN ............................................................±0.3V

CSP, CSN or BAT to GND ........................... –0.3V to 28V

CSP to CSN ............................................................±0.3V

BOOST to GND ........................................... –0.3V to 36V

BOOST to SW............................................... –0.3V to 7V

SHDN

or V

FB

to GND .................................... –0.3V to 7V

CHRG

or

ICL

to GND .................................. –0.3V to 30V

Operating Temperature Range

(Note 2) ............................................. –40°C to 125°C

Junction Temperature (Note 3) ............................. 125°C

Storage Temperature Range .................. –65°C to 150°C

20 19 18 17 16

CLN 1

CLP 2

INFET 3

DCIN 4

GND 5

UF PACKAGE

20-LEAD (4mm 4mm) PLASTIC QFN

T

JMAX

= 125°C,

JA

= 37°C/W

EXPOSED PAD (PIN 21) IS GND, MUST BE SOLDERED TO PCB

orDer inForMaTion

LEAD FREE FINISH

LTC4012CUF-3#PBF

LTC4012IUF-3#PBF

TAPE AND REEL

LTC4012CUF-3#TRPBF

LTC4012IUF-3#TRPBF

PART MARKING*

40123

PACKAGE DESCRIPTION

20-Lead (4mm

×

4mm) Plastic QFN

20-Lead (4mm

×

4mm) Plastic QFN

TEMPERATURE RANGE

0°C to 85°C

–40°C to 125°C

Consult LTC Marketing for parts specified with wider operating temperature ranges. *The temperature grade is identified by a label on the shipping container.

Consult LTC Marketing for information on non-standard lead based finish parts.

For more information on lead free part marking, go to:

http://www.linear.com/leadfree/

For more information on tape and reel specifications, go to:

http://www.linear.com/tapeandreel/

40123fb

LTC4012-3

elecTrical characTerisTics

SYMBOL

V

TOL

I

VFB

R

ON

I

LEAK-FBDIV

V

BOV

I

TOL

PARAMETER

V

BAT

Accuracy (See Test Circuits)

V

FB

Input Bias Current

FBDIV On Resistance

FBDIV Output Leakage Current

V

FB

Overvoltage Threshold

Charge Current Accuracy with R

IN

= 3.01k,

6V < BAT < 18V

R

PROG

= 26.7k

C-Grade

I-Grade

V

SENSE

= 0mV, PROG = 1.2V

A

I

V

CS-MAX

V

C10

V

REV

V

CL

I

CLN

V

ICL

CLP Supply

OVR

V

UVLO

V

UV(HYST)

I

CLPO

Shutdown

V

IL

V

IH

R

IN

I

CLPS

I

LEAK-BAT

I

LEAK-CSN

I

LEAK-CSP

I

LEAK-SW

SHDN

Input Voltage Low

SHDN

Input Voltage High

SHDN

Pull-Down Resistance

CLP Shutdown Current

BAT Leakage Current

CSN Leakage Current

CSP Leakage Current

SW Leakage Current

CLP = 12V, DCIN = 0V

SHDN

= 0V

SHDN

= 0V or DCIN = 0V,

0V ≤ CSP = CSN = BAT ≤ 18V

SHDN

= 0V or DCIN = 0V,

0V ≤ CSP = CSN = BAT ≤ 20V

SHDN

= 0V or DCIN = 0V,

0V ≤ CSP = CSN = BAT ≤ 20V

SHDN

= 0V or DCIN = 0V,

0V ≤ SW ≤ 20V

l

The

l

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T

A

= 25°C. DCIN = 20V, BAT = 12V, GND = 0V unless otherwise noted. (Note 2)

CONDITIONS

l

MIN

–0.5

–0.8

–1.0

TYP

MAX

0.5

0.8

1.0

UNITS

%

nA

Ω

µA

V

%

µA

mV

nA

mV

V

mV

mA

mV

V

kΩ

Charge Voltage Regulation

C-Grade

I-Grade

V

FB

= 1.2V

I

LOAD

= 100µA

SHDN

= 0V, FBDIV = 0V

l

±20

85

–1

1.235

–4

–5

–9.5

–12.75

–1.78

l

190

1

1.32

4

5

9.5

0

1.281

Charge Current Regulation

l

–11.67

–1.66

195

325

400

253

100

±100

–10.95

–1.54

250

265

430

460

295

103

104

108

–2

28

Current Sense Amplifier Gain (PROG ∆I) with

R

IN

= 3.01k, 6V < BAT < 18V

Maximum Peak Current Sense Threshold Voltage

per Cycle (R

IN

= 3.01k)

C/10 Indicator Threshold Voltage

Reverse Current Threshold Voltage

Current Limit Threshold

V

SENSE

Step from 0mV to 5mV,

PROG = 1.2V

ITH = 2V, C-Grade

ITH = 2V, I-Grade

ITH = 5V

PROG Falling

CLP – CLN

C-Grade

I-Grade

CLN = CLP

(CLP – CLN) – V

CL

l

140

125

340

180

97

96

92

–8

6

Input Current Regulation

CLN Input Bias Current

ICL

Indicator Threshold

Operating Voltage Range

CLP Undervoltage Lockout Threshold

UVLO Threshold Hysteresis

CLP Operating Current

–5

CLP Increasing

CLP = 20V, No Gate Loads

l

4.65

4.85

200

2

5.25

3

300

1.4

40

15

350

–1.5

–1

0

26

500

1.5

2

µA

40123fb

LTC4012-3

elecTrical characTerisTics

SYMBOL

INTV

DD

∆V

DD

I

DD

V

ACP

I

ITH

f

TYP

f

MIN

DC

MAX

t

R-TG

t

F-TG

t

R-BG

t

F-BG

t

NO

I

DCIN

V

FTO

V

FR

V

RTO

V

OL(INFET)

V

OH(INFET)

t

IF(ON)

t

IF(OFF)

V

OL

I

LEAK

I

C10

PARAMETER

Output Voltage

Load Regulation

Short-Circuit Current (Note 5)

AC Present Charge Enable Threshold Voltage

INTV

DD

Regulator

No Load

I

DD

= 20mA

INTV

DD

= 0V

DCIN – BAT, DCIN Rising

C-Grade

I-Grade

ITH = 1.4V

467

C

LOAD

= 3.3nF

C

LOAD

= 3.3nF

C

LOAD

= 3.3nF, 10% – 90%

C

LOAD

= 3.3nF, 90% – 10%

C

LOAD

= 3.3nF, 10% – 90%

C

LOAD

= 3.3nF, 90% – 10%

C

LOAD

= 3.3nF, 10% – 10%

0V ≤ DCIN ≤ CLP

DCIN-CLP, DCIN Rising

DCIN-CLP

DCIN-CLP DCIN Falling

,

DCIN-CLP = 0.1V, I

INFET

=1µA

DCIN-CLP = –0.1V, I

INFET

=–5µA

To CLP-INFET > 3V, C

INFET

= 1nF

To CLP-INFET < 1.5V, C

INFET

= 1nF

I

LOAD

= 100µA, PROG = 1.2V

SHDN

= 0V, DCIN = 0V, V

OUT

= 20V

CHRG

= 2.5V

l

The

l

denotes the specifications which apply over the full operating

temperature range, otherwise specifications are at T

A

= 25°C. DCIN = 20V, BAT = 12V, GND = 0V unless otherwise noted. (Note 2)

CONDITIONS

MIN

4.85

50

TYP

5

–0.4

85

MAX

5.15

–1

130

UNITS

V

%

mA

Switching Regulator

350

300

500

–40/+90

550

25

99

60

50

60

110

–10

15

–45

–6.5

–250

85

2.5

25

–25

60

35

–15

–5

250

180

6

500

–10

15

25

10

38

110

633

20

98

650

700

mV

µA

kHz

%

ns

µA

mV

V

mV

µs

mV

µA

ITH Current

Typical Switching Frequency

Minimum Switching Frequency

Maximum Duty Cycle

TGATE Rise Time

TGATE Fall Time

BGATE Rise Time

BGATE Fall Time

TGATE, BGATE Non-Overlap Time

DCIN Input Current

Forward Turn-On Voltage (DCIN Detection Threshold)

Forward Regulation Voltage

Reverse Turn-Off Voltage

INFET Output Low Voltage, Relative to CLP

INFET Output High Voltage, Relative to CLP

INFET Turn-On Time

INFET Turn-Off Time

Output Voltage Low

Output Leakage

CHRG

C/10 Current Sink

PowerPath Control

Indicator Outputs

Note 1:

Stresses beyond those listed under Absolute Maximum Ratings

may cause permanent damage to the device. Exposure to any Absolute

Maximum Rating condition for extended periods may affect device

reliability and lifetime.

Note 2:

The LTC4012C-3 is guaranteed to meet performance specifications

over the 0°C to 85°C operating temperature range. The LTC4012I-3 is

guaranteed to meet performance specifications over the –40°C to 125°C

operating temperature range.

Note 3:

Operating junction temperature T

J

(in °C) is calculated from

the ambient temperature T

A

and the total continuous package power

dissipation P

D

(in watts) by the formula T

J

= T

A

+ (θ

JA

• PD). Refer to the

Applications Information section for details.

Note 4:

All currents into device pins are positive; all currents out of device

pins are negative. All voltages are referenced to GND, unless otherwise

specified.

Note 5:

Output current may be limited by internal power dissipation. Refer

to the Applications Information section for details.

40123fb

LTC4012-3

(T

A

= 25°C unless otherwise noted. L = IHLP-2525 6.8µH)

Efficiency at DCIN = 20V, BAT = 8V

100

R

SENSE

= 33m

R

IN

= 3.01k

10000

100

R

SENSE

= 33m

R

IN

= 3.01k

95

POWER LOSS(mW)

EFFICIENCY

90

POWER LOSS

1000

EFFICIENCY (%)

EFFICIENCY

POWER LOSS(mW)

Typical perForMance characTerisTics

Efficiency at DCIN = 20V, BAT = 12V

10000

95

EFFICIENCY (%)

90

POWER LOSS

1000

85

80

0

0.5

1

1.5

2

CHARGE CURRENT (A)

2.5

3

100

80

0

0.5

4012-3 G01

1

1.5

2

CHARGE CURRENT (A)

2.5

3

100

4012-3 G02

Efficiency at DCIN = 20V, BAT = 16V

100

EFFICIENCY

95

POWER LOSS(mW)

EFFICIENCY (%)

V

FB

ERROR (%)

10000

0.10

0.08

0.06

0.04

0.02

0

–0.02

–0.04

–0.06

–0.08

3

100

–0.10

V

FB

Line Regulation

LTC4012-3 TEST CIRCUIT

90

POWER LOSS

1000

85

R

SENSE

= 33m

R

IN

= 3.01k

80

0

0.5

1

1.5

2

CHARGE CURRENT (A)

2.5

5

10

4012-3 G03

20

15

CLP (V)

25

30

4012-3 G04

FBDIV Pin R

ON

vs Battery Voltage

300

275

250

225

R

ON

( )

200

175

150

125

100

75

0

5

15

10

BAT (V)

20

25

4012-3 G05

Battery Load Dump

BATTERY VOLTAGE

(500mV/DIV)

2A

12.1V

1A

3A

RECONNECT

DISCONNECT

TIME (1ms/DIV)

CLP = 20V

V

OUT

= 12.3V

4012-3 G06

CLP = BAT + 3V

(CLP ≥ 6V)

1A

LOAD

STATE

40123fb

LTC4012CUF-3

LTC4012CUF-3 Overview

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