LINEAR TECHNOLOGY LTC4060 Technical data

FEATURES

■

Complete Fast Charger Controller for Single,
2-, 3- or 4-Series Cell NiMH/NiCd Batteries

■

No Firmware or Microcontroller Required

■

Termination by –∆V, Maximum Voltage or
Maximum Time

■

No Sense Resistor or Blocking Diode Required

■

Automatic Recharge Keeps Batteries Charged

■

Programmable Fast Charge Current: 0.4A to 2A

■

Accurate Charge Current: ±5% at 2A

■

Fast Charge Current Programmable Beyond 2A with
External Sense Resistor

■

Automatic Detection of Battery

■

Precharge for Heavily Discharged Batteries

■

Optional Temperature Qualified Charging

■

Charge and AC Present Status Outputs Can Drive LED

■

Automatic Sleep Mode with Input Supply Removal

■

Negligible Battery Drain in Sleep Mode: <1µA

■

Manual Shutdown

■

Input Supply Range: 4.5V to 10V

■

Available in 16-Lead DFN and TSSOP Packages

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APPLICATIO S

■

Portable Computers, Cellular Phones and PDAs

■

Medical Equipment

■

Charging Docks and Cradles

■

Portable Consumer Electronics

LTC4060

Standalone Linear NiMH/NiCd

Fast Battery Charger

U

DESCRIPTIO

The LTC®4060 is a complete fast charging system for NiMH
or NiCd batteries. Just a few external components are
needed to design a standalone linear charging system.

An external PNP transistor provides charge current that is
user programmable with a resistor. A small external capaci­tor sets the maximum charge time. No external current
sense resistor is needed, and no blocking diode is required.

The IC automatically senses the DC input supply and bat­tery insertion or removal. Heavily discharged batteries are
initially charged at a C/5 rate before a fast charge is applied.
Fast charge is terminated using the – ∆V detection method.
Backup termination consists of a programmable timer and
battery overvoltage detector. An optional external NTC ther­mistor can be used for temperature-based qualification of
charging. An optional programmable recharge feature au­tomatically recharges batteries after discharge.

Manual shutdown is accomplished with the SHDN pin, while
removing input power automatically puts the LTC4060 into
sleep mode. During shutdown or sleep mode, battery drain
is <1µA.

The LTC4060 is available in both low profile (0.75mm) 16­pin 5mm × 3mm DFN and 16-lead TSSOP packages. Both
feature exposed metal die mount pads for optimum ther­mal performance.

, LTC and LT are registered trademarks of Linear Technology Corporation.

TYPICAL APPLICATIO

2-Cell, 2A Standalone NiMH Fast Charger with

Optional Thermistor and Charge Indicator

330Ω

“CHARGE”

NTC

698Ω

SHDN

CHRG

NTC

PROG

ARCT

SEL0

SEL1

U

V

IN =

V

CC

SENSE

LTC4060

PAUSE

GND

5V

ACP

DRIVE

BAT

TIMER

CHEM

1.5nF

4060 TA01

+

NiMH
BATTERY

2-Cell NiMH Charging Profile

3.40

–∆V

TERMINATION

3.30

3.20

BATTERY VOLTAGE (V)

3.10
0

10 20 30 40

CHARGE TIME (MINUTES)

50

60

4060 TA01b

4060f

1

LTC4060

WW

W

U

ABSOLUTE MAXIMUM RATINGS

(Note 1)

VCC to GND ............................................... –0.3V to 11V

Input Voltage

SHDN, NTC, SEL0, SEL1, PROG, ARCT,

BAT, CHEM, TIMER, PAUSE ...... –0.3V to VCC + 0.3V

Output Voltage

CHRG, ACP, DRIVE ................... –0.3V to VCC + 0.3V

Output Current (SENSE) ...................................... –2.2A

Short-Circuit Duration (DRIVE) ...................... Indefinite

U

W

U

PACKAGE/ORDER INFORMATION

TOP VIEW

DRIVE

1

BAT

2

SENSE

3

TIMER

4

SHDN

5

PAUSE

6

PROG

7

ARCT

8

DHC16 PACKAGE

16-LEAD (5mm × 3mm) PLASTIC DFN

T

= 125°C, θJA = 37°C/W

JMAX

EXPOSED PAD (PIN 17) IS GND

MUST BE SOLDERED TO PCB TO OBTAIN

= 37°C/W OTHERWISE θJA = 140°C

θ

JA

16

GND

15

CHRG

14

V

CC

ACP

13

17

CHEM

12

NTC

11

SEL1

10

SEL0

9

ORDER PART

NUMBER

LTC4060EDHC

DHC PART

MARKING

4060

Operating Ambient Temperature Range

(Note 2) ............................................. – 40°C to 85°C

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

Storage Temperature Range

TSSOP Package ............................... – 65°C to 150°C

DFN Package .................................... –65°C to 125°C

Lead Temperature (Soldering, 10 sec)

TSSOP Package ................................................ 300°C

TOP VIEW

1

DRIVE

2

BAT

3

SENSE

4

TIMER

SHDN

PAUSE

PROG

ARCT

16-LEAD PLASTIC TSSOP

T

JMAX

EXPOSED PAD (PIN 17) IS GND

MUST BE SOLDERED TO PCB TO OBTAIN

θJA = 37°C/W OTHERWISE θJA = 135°C

17

5

6

7

8

FE PACKAGE

= 125°C, θJA = 37°C/W

GND

16

CHRG

15

V

14

CC

ACP

13

CHEM

12

NTC

11

SEL1

10

SEL0

9

ORDER PART

NUMBER

LTC4060EFE

FE PART

MARKING

4060EFE

Consult LTC Marketing for parts specified with wider operating temperature ranges.

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at TA = 25°C. VCC = 5V, V

The ● indicates specifications which apply over the full operating

= 2.8V, GND = 0V unless otherwise specified. All

BAT

currents into the device pins are positive and all currents out of the device pins are negative. All voltages are referenced to GND
unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

VCC Supply

V

I

I

I

I

V

V

CC

SD

BSD

BSL

CC

UVI1

UVD1

Operating Voltage Range (Note 4) ● 4.50 10 V

VCC Supply Current (Note 9) I

= 2mA (R

PROG

PAUSE = V

CC

= 698Ω), 2.9 4.3 mA

PROG

VCC Supply Shutdown Current SHDN = 0V 250 325 µA

Battery Pin Leakage Current in Shutdown (Note 5) V

Battery Pin Leakage Current in Sleep (Note 6) VCC = 0V, V

= 2.8V, SHDN = 0V –1 0 1 µA

BAT

= 5.6V –1 0 1 µA

BAT

Undervoltage Lockout Exit Threshold SEL0 = 0, SEL1 = 0 and SEL0 = VCC, ● 4.25 4.36 4.47 V

SEL1 = 0, V

Increasing

CC

Undervoltage Lockout Entry Threshold SEL0 = 0, SEL1 = 0 and SEL0 = VCC, ● 4.15 4.26 4.37 V

SEL1 = 0, V

Decreasing

CC

4060f

2

LTC4060

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at T

The ● indicates specifications which apply over the full operating

= 25°C. VCC = 5V, V

A

= 2.8V, GND = 0V unless otherwise specified. All

BAT

currents into the device pins are positive and all currents out of the device pins are negative. All voltages are referenced to GND
unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

UVI2

V

UVD2

V

UVI3

V

UVD3

V

UVH

Charging Performance

I

FCH

I

FCL

I

PCH

I

PCL

I

BRD

V

BR

V

BRH

V

BOV

V

BOVH

V

FCQ

V

FCQH

V

IDT

V

IDTH

V

MDV

V

PROG

V

ART

V

ARDT

V

ARH

V

ARDEF

V

ARDIS

I

ARL

V

CLD

V

CLDH

V

HTI

Undervoltage Lockout Exit Threshold SEL0 = 0, SEL1 = VCC, VCC Increasing ● 6.67 6.81 6.95 V

Undervoltage Lockout Entry Threshold SEL0 = 0, SEL1 = VCC, VCC Decreasing ● 6.57 6.71 6.85 V

Undervoltage Lockout Exit Threshold SEL0 = VCC, SEL1 = VCC, VCC Increasing ● 8.28 8.47 8.65 V

Undervoltage Lockout Entry Threshold SEL0 = VCC, SEL1 = VCC, VCC Decreasing ● 8.18 8.37 8.55 V

Undervoltage Lockout Hysteresis For All SEL0, SEL1 Options 100 mV

High Fast Charge Current (Notes 7, 10) R

Low Fast Charge Current (Note 7) R

High Precharge Current (Note 7) R

Low Precharge Current (Note 7) R

Battery Removal Detection Bias Current 4.5V < VCC < 10V, V

Battery Removal Threshold Voltage (Note 8) V

Battery Removal Threshold Hysteresis Voltage V

= 698Ω, 5V < VCC < 10V ● 1.9 2 2.1 A

PROG

= 3480Ω, 4.5V < VCC < 10V ● 0.35 0.4 0.45 A

PROG

= 698Ω, 4.5V < VCC < 10V 320 400 480 mA

PROG

= 3480Ω, 4.5V < VCC < 10V 40 80 120 mA

PROG

= VCC – 0.4V ● –450 –300 –160 µA

BAT

Increasing, 4.5V < VCC < 10V ● 1.95 2.05 2.15 V

CELL

Decreasing 50 mV

CELL

(Note 8)

Battery Overvoltage Threshold (Note 8) V

Battery Overvoltage Threshold Hysteresis (Note 8) V

Fast Charge Qualification Threshold Voltage V

Increasing, 4.5V < VCC < 10V ● 1.85 1.95 2.05 V

CELL

Decreasing 50 mV

CELL

Increasing, 4.5V < VCC < 10V 840 900 960 mV

CELL

(Note 8)

Fast Charge Qualification Threshold Hysteresis V

Decreasing 50 mV

CELL

Voltage (Note 8)

Initial Delay Hold-Off Threshold Voltage (Note 8) V

Initial Delay Hold-Off Threshold Hysteresis Voltage V

Increasing, 4.5V < VCC < 10V 1.24 1.3 1.36 V

CELL

Decreasing 50 mV

CELL

(Note 8)

–∆V Termination (Note 8) CHEM = VCC (NiCd) ● 11 16 21 mV

CHEM = 0V (NiMH)

Program Pin Voltage 4.5V < VCC < 10V, R

= 635Ω ● 1.45 1.5 1.54 V

PROG

● 5814mV

and 3480Ω

Automatic Recharge Programmed Threshold V
Voltage Accuracy (Note 8) 4.5V < V

Automatic Recharge Default Threshold Voltage V
Accuracy (Note 8) 4.5V < V

Automatic Recharge Threshold Voltage Hysteresis V

Decreasing, V

CELL

CELL

CELL

< 10V

CC

Decreasing, V

< 10V

CC

Increasing 50 mV

= 1.1V, ● 1.065 1.1 1.135 V

ARCT

= VCC, ● 1.235 1.3 1.365 V

ARCT

(Note 8)

Automatic Recharge Pin Default Enable Threshold V

CC

V

CC

Voltage – 0.8 – 0.2

Automatic Recharge Pin Disable Threshold 250 650 mV
Voltage

Automatic Recharge Pin Pull-Down Current V

NTC Pin Cold Threshold Voltage V

NTC Pin Cold Threshold Hysteresis Voltage V

NTC Pin Hot Charge Initiation Threshold Voltage V

= 1.3V ● 0.15 1.5 µA

ARCT

Decreasing, 4.5V < VCC < 10V ● 0.83 • 0.86 • 0.89 • V

NTC

Increasing 150 mV

NTC

Decreasing, 4.5V < VCC < 10V ● 0.47 • 0.5 • 0.53 • V

NTC

V

CC

V

CC

V

CC

V

CC

V

CC

V

CC

4060f

V

3

LTC4060

ELECTRICAL CHARACTERISTICS

temperature range, otherwise specifications are at T

The ● indicates specifications which apply over the full operating

= 25°C. VCC = 5V, V

A

= 2.8V, GND = 0V unless otherwise specified. All

BAT

currents into the device pins are positive and all currents out of the device pins are negative. All voltages are referenced to GND
unless otherwise specified.

SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS

V

HTIH

V

HTC

V

HTCH

V

NDIS

I

NL

t

ACC

Output Drivers

I

DRV

R

DRV

V

OL

I

OH

Control Inputs

V

IT

V

ITH

I

IPD

I

IPU

NTC Pin Hot Charge Initiation Hysteresis Voltage V

NTC Pin Hot Charge Cutoff Threshold Voltage V

NTC Pin Hot Charge Cutoff Hysteresis Voltage V

Increasing 100 mV

NTC

Decreasing, 4.5V ≤ VCC ≤ 10V ● 0.37 • 0.4 • 0.43 • V

NTC

Increasing 100 mV

NTC

V

CC

V

CC

V

CC

NTC Pin Disable Threshold Voltage 25 250 mV

NTC Pin Pull-Down Current V

Timer Accuracy R

Drive Pin Sink Current V

Drive Pin Resistance to V

CC

ACP, CHRG Output Pins Low Voltage I

ACP, CHRG Output Pins High Leakage Current Outputs Inactive, V

= 2.5V ● 0.15 1.5 µA

NTC

= 698Ω, C

PROG

= 3480Ω, C

R

PROG

= 4V ● 40 70 120 mA

DRIVE

V

= 4V, Not Charging 4700 Ω

DRIVE

= I

ACP

= 10mA 0.8 V

CHRG

= 1.2nF and –15 0 15 %

TIMER

= 470pF

TIMER

= V

CHRG

ACP

= V

CC

–2 2 µA

SHDN, SEL0, SEL1, CHEM, PAUSE Pins Digital VCC = 10V 350 650 mV
Input Threshold Voltage

SHDN, SEL0, SEL1, CHEM, PAUSE Pins Digital 50 mV
Input Hysteresis Voltage

SHDN, SEL0, SEL1, CHEM Pins Digital Input VCC = 10V, VIN = V

CC

0.4 2 µA

Pull-Down Current

PAUSE Pin Digital Input Pull-Up Current VIN = GND –2 –0.4 µA

Note 1: Absolute Maximum Ratings only indicate limits for survivability.
Operating the device beyond these limits may result in permanent damage.
Continuous or extended application of these maximum levels may
adversely affect device reliability.

Note 2: The LTC4060 is guaranteed to meet performance specifications
from 0°C to 70°C ambient temperature range and 0°C to 85°C junction
temperature range. Specifications over the –40°C to 85°C operating
ambient temperature range are assured by design, characterization and
correlation with statistical process controls.

Note 3: This IC includes overtemperature protection that is intended to
protect the device during momentary overload conditions. Overtempera­ture protection is activated at a temperature of approximately 145°C,
which is above the specified maximum operating junction temperature.
Continuous operation above the specified maximum operation temperature
may result in device degradation or failure. Operating junction temperature

(in °C) is calculated from the ambient temperature TA and the average

T

J

power dissipation P

TJ = TA + θ

Note 4: Short duration drops below the minimum V

(in watts) by the formula:

D

• P

JA

D

specification of

CC

several microseconds or less are ignored by the undervoltage detection
circuit.

Note 5: Assumes that the external PNP pass transistor has negligible B-C
reverse leakage current when the collector is biased at 2.8V (V
charged cells in series) and the base is biased at V

CC

.

BAT

for two

Note 6: Assumes that the external PNP pass transistor has negligible B-E
reverse leakage current when the emitter is biased at 0V (V
base is biased at 5.6V (V

for four charged cells in series).

BAT

) and the

CC

Note 7: The charge current specified is the regulated current through the
internal current sense resistor that flows into the external PNP pass
transistor’s emitter. Actual battery charging current is slightly less and
depends upon PNP alpha.

Note 8: Given as a per cell voltage (V

/Number of Cells).

BAT

Note 9: Supply current includes the current programming resistor current
of 2mA. The charger is paused and not charging the battery.

Note 10: The minimum V

supply is set at 5V during this test to

CC

compensate for voltage drops due to test socket contact resistance and 2A
of current. This ensures that the supply voltage delivered to the device
under test does not fall below the UVLO entry threshold. Specification at
the minimum V

of 4.5V is assured by design and characterization.

CC

4060f

4

UW

TEMPERATURE (°C)

–50

0.5

1.0

1.7

25 75

4060 G09

0

–0.5

–25 0

50 100 125

–1.0

–1.5

1.5

ERROR (%)

VCC = 10V

VCC = 4.5V

R

PROG

= 3480Ω

C

TIMER

= 470pF

R

PROG

= 698Ω

C

TIMER

= 1.2nF

TYPICAL PERFOR A CE CHARACTERISTICS

LTC4060

NiMH Battery Charging
Characteristics at 1C Rate

1.70
TA = 25°C

–∆V TERMINATION

1.65

1.60

CELL VOLTAGE (V)

1.55

0

10 20 30 40

CHARGE TIME (MINUTES)

NiCd Battery Charging
Characteristics at C/2 Rate

1.65

1.60

–∆V TERMINATION

1.55

1.50

CELL VOTLAGE (V)

1.45

NiCd Battery Charging
Characteristics at 1C Rate

1.7
TA = 25°C

–∆V TERMINATION

1.6

1.5

CELL VOLTAGE (V)

1.4
0

50

60

4060 G01

10 20 30 40

CHARGE TIME (MINUTES)

I

vs Temperature and

FCH

50

60

4060 G02

Supply Voltage

2.010

2.005

(A)

2.000

FCH

I

1.995

VCC = 10V

VCC = 4.5V

NiMH Battery Charging
Characteristics at C/2 Rate

1.60
TA = 25°C

1.55

1.50

1.45

CELL VOTLAGE (V)

1.40

1.35

020

I

–∆V TERMINATION

60

40

CHARGE TIME (MINUTES)

vs Temperature and

FCL

Supply Voltage

402

401

(mA)

400

FCL

I

399

80

VCC = 10V

VCC = 4.5V

100

120

140

4060 G03

1.40

–260

(µA)

–300

BRD

I

–340

020

–50

60

40

CHARGE TIME (MINUTES)

I

vs Temperature and

BRD

Supply Voltage

VCC = 10V

–25 0 25 50

TEMPERATURE (°C)

80

100

120

4060 G04

VCC = 4.5V

75 100 125

4060 G07

140

1.990
–50

–25 0 25 50

V

MDV

Supply Voltage

18

16

14

12

(mV)

MDV

10

V

8

6

4

–50

–25 0

TEMPERATURE (°C)

75 100 125

vs Temperature and

NiCd

4.5V ≤ V

4.5V ≤ V

TEMPERATURE (°C)

≤ 10V

CC

NiMH

≤ 10V

CC

50 100 125

25 75

4060 G05

4060 G08

398

–50

–25 0 25 50

t

vs Temperature and

ACC

Supply Voltage

TEMPERATURE (°C)

75 100 125

4060 G06

4060f

5

LTC4060

U

UU

PI FU CTIO S

DRIVE (Pin 1): Base Drive Output for the External PNP
Pass Transistor. Provides a controlled sink current that
drives the base of the PNP. This pin has current limit
protection for the LTC4060.

BAT (Pin 2): Battery Voltage Sense Input Pin. The LTC4060
uses the voltage on this pin to monitor battery voltage and
control the battery current during charging. An internal
resistor divider is connected to this pin which is discon­nected when in shutdown or when no power is applied to
VCC.

SENSE (Pin 3): Charge Current Sense Node Input. Current
from V
tor and reappears at the SENSE pin to supply current to the
external PNP emitter. The PNP collector provides charge
current directly to the battery.

TIMER (Pin 4): Charge Timer Input. A capacitor connected
between TIMER and GND along with a resistor connected
from PROG to GND programs the charge cycle timing
limits.

SHDN (Pin 5): Active Low Shutdown Control Logic Input.
When pulled low, charging stops and the LTC4060 supply
current is minimized.

PAUSE (Pin 6): Pause Enable Logic Input. The charger can
be paused, turning off the charge current, disabling termi­nation and stopping the timer when this pin is high. A low
level will resume the charging process.

PROG (Pin 7): Charge Current Programming Input. Pro­vides a virtual reference of 1.5V for an external resistor
(R

PROG

battery charge current. The fast charge current will be 930
times the current through this resistor. This voltage is also
usable as system voltage reference.

passes through the internal current sense resis-

CC

) tied between this pin and GND that programs the

SEL0, SEL1 (Pins 9, 10): Number of Cells Selection Logic
Input. For single cell, connect both pins to GND. For two
cells, connect SEL1 to GND and SEL0 to V
cells, SEL1 connects to V
cells, connect both pins to V

NTC (Pin 11): Battery Temperature Input. An external NTC
thermistor network may be connected to NTC to provide
temperature-based charge qualification. Connecting NTC
to GND inhibits this function.

CHEM (Pin 12): Battery Chemistry Selection Logic Input.
When connected to a high level NiCd fast charge –∆V
termination parameters are used. A low level selects NiMH
parameters.

ACP (Pin 13): Open-Drain Power Supply Status Output.
When V
old, the ACP pin will pull to ground. Otherwise the pin is
high impedance. This output is capable of driving an LED.

VCC (Pin 14): Power Input. This pin can be bypassed to
ground with a capacitance of 1µF.

CHRG (Pin 15): Open-Drain Charge Indicator Status Out­put. The LTC4060 indicates it is providing charge to the
battery by driving this pin to GND. If charging is paused or
suspended due to abnormal battery temperature, the pin
remains pulled to GND. Otherwise the pin is high imped­ance. This output can drive an LED.

GND (Pin 16): Ground. This pin provides a ground for the
internal voltage reference and other circuits. All voltage
thresholds are referenced to this pin.

Exposed Pad (Pin 17): Thermal Connection. Internally
connected to GND. Solder to PCB ground for optimum
thermal performance.

is greater than the undervoltage lockout thresh-

CC

and SEL0 to GND. For four

CC

.

CC

For three

CC.

ARCT (Pin 8): Autorecharge Threshold Programming
Input. When the average cell voltage falls below this
threshold, charging is reinitiated. The voltage on this pin
is conveniently derived by using two series PROG pin
resistors and connecting to their common. Connecting
ARCT to VCC invokes a default threshold of 1.3V. Connect­ing ARCT to GND inhibits autorecharge.

6

4060f