Datasheet TK732xx Datasheet (TOKO)

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Page 1

PULSE

CONTROL

GND

BASE

NOISE

BYPASS

SENSE

查询TK73211MCLH供应商

TK732xx

LOW DROPOUT REGULATOR

FEATURES

■ Up to 5 A Output Current Capability With External

PNP Transistor

■ Internal Short Circuit Protection

■ Excellent Load Regulation

■ CMOS/TTL-Compatible On/Off Switch

■ Internal Reverse Bias Current Protection Switch

■ Internal Thermal Shutdown

■ Broad Operating Voltage Range

■ High Impedance V

Pin (Off Mode)

SENSE

■ Continuous and Pulsed Current Modes

DESCRIPTION

The TK732xx is a controller IC for a low dropout voltage regulator. The TK732xx and the external PNP power transistor provide standard output voltages from 2 to 11 V and output current from 100 mA to 5 A. By utilizing an external PNP power transistor, low dropout voltage at high current can be readily achieved. The internal electronic switch can be controlled by TTL or CMOS logic levels. The device is in the “on” state when the control pin is pulled to a high logic level. A pin for a bypass capacitor, which connects to the internal circuitry, is provided to lower the overall output noise level.

APPLICATIONS

■ Battery Powered Systems

■ Cellular/Cordless Telephones

■ Radio Control Systems

■ Wireless Communications Systems

■ Portable Instrumentations

■ Portable Computers

■ Personal Digital Assistants

■ Local Area Network (LAN) Receivers

■ Lithium Ion Battery Chargers

■ Power Recovery for Microprocessors

TK732xx

01S

The current limit characteristics can be configured as continuous (constant current) or pulsed (cycling). An internal thermal shutdown circuit limits the junction temperatures to below 150 °C. In the “off” mode, the output of the regulator becomes a high impedance. This prevents the output capacitor from being rapidly discharged for backup to the load.

ORDERING INFORMATION

TK732 M L

Grade

Voltage Code

Package Code

VOLTAGE CODE

20 = 2.0 V * 32 = 3.2 V 44 = 4.4 V 21 = 2.1 V * 33 = 3.3 V 45 = 4.5 V 22 = 2.2 V * 34 = 3.4 V 46 = 4.6 V 23 = 2.3 V * 35 = 3.5 V 47 = 4.7 V 24 = 2.4 V 36 = 3.6 V 48 = 4.8 V 25 = 2.5 V 37 = 3.7 V 49 = 4.9 V 26 = 2.6 V 38 = 3.8 V 50 = 5.0 V 27 = 2.7 V 39 = 3.9 V 55 = 5.5 V * 28 = 2.8 V 40 = 4.0 V 70 = 7.0 V * 29 = 2.9 V 41 = 4.1 V 80 = 8.0 V 30 = 3.0 V 42 = 4.2 V 11 = 11.0 V 31 = 3.1 V 43 = 4.3 V

January 1999 TOKO, Inc. Page 1

TAPE/REEL CODE

L: Tape Left

TEMP. RANGE

C: -30 to 80 C ** I : -40 to 85

* Unavailable with I Rank ** unless Otherwise Specified *** TK73241MCLH, TK73242MCLH Available Only

Tape/Reel Code Temp. Code

PACKAGE CODE

M: SOT-23L-8

GRADE

None: Standard 2% H: High (Special) **

CONTROL

BLOCK DIAGRAM

PK C

ON/OFF

CIRCUIT

BANDGAP

REFERENCE

GND

NOISE BYPASS

PULSE

THERMAL

SENSOR

BASEVSENSE

LEAKAGE

PROTECTION

Page 2

TK732xx

ABSOLUTE MAXIMUM RATINGS (STANDARD DEVICES) (NOTE 6)

Supply Voltage Range ............................................ 19 V

Power Dissipation (Note 1) ................................ 600 mW

Reverse Bias Voltage Range ..................................... 6 V

Noise Bypass Pin Terminal Voltage Range ............... 5 V

Control Pin Terminal Voltage Range........................ 14 V

Storage Temperature Range ................... -55 to +150 °C

TK732xx ELECTRICAL CHARACTERISTICS (STANDARD DEVICES)

Test conditions: VIN = V

LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU

OUT(TYP)

+ 1 V, TA = 25 °C, unless otherwise specified.

Operating Temperature Range ...................-30 to +80 °C

Extended Temperature Range................... -40 to +85 °C

Operating Voltage Range............................ 1.8 to 14.0 V

Junction Temperature ........................................... 150 °C

Lead Soldering Temperature (10 s) ...................... 235 °C

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Page 2 January 1999 TOKO, Inc.

Page 3

TK732xx

TK732xx ELECTRICAL CHARACTERISTICS (STANDARD DEVICES) CONT.

Note 1: Power dissipation is 600 mW when mounted as recommended. Derate at 4.8 mW/°C for operation above 25 °C. Note 2: Refer to :Definition of Terms.” Note 3: Ripple rejection and noise voltage are affected by the value and characteristics of the capacitor used. Note 4: This pin is used for Pulse Current Limit Mode. When selecting Continuous Current Limit Mode, this pin is connected to GND. Note 5: Not applicable for V Note 6: The voltage applied to any pin must be greater than -0.4 V. Gen. Note: Parameters with min. or max. values are 100% tested at TA = 25 °C.

TK732xx ELECTRICAL CHARACTERISTICS TABLE 1 (STANDARD DEVICES)

Test Conditions: VIN = V

Output Voltage Voltage Code V

2.0 V 20 1.940 V 2.060 V

2.1 V 21 2.040 V 2.160 V

2.2 V 22 2.140 V 2.260 V

2.3 V 23 2.240 V 2.360 V

2.4 V 24 2.340 V 2.460 V 2.300 V 2.500 V

2.5 V 25 2.440 V 2.560 V 2.400 V 2.600 V

2.6 V 26 2.540 V 2.660 V 2.500 V 2.700 V

2.7 V 27 2.640 V 2.760 V 2.600 V 2.800 V

2.8 V 28 2.740 V 2.860 V 2.700 V 2.900 V

2.9 V 29 2.840 V 2.960 V 2.800 V 3.000 V

3.0 V 30 2.940 V 3.060 V 2.900 V 3.100 V

3.1 V 31 3.040 V 3.160 V 3.000 V 3.200 V

3.2 V 32 3.140 V 3.260 V 3.095 V 3.305 V

3.3 V 33 3.240 V 3.360 V 3.190 V 3.410 V

3.4 V 34 3.335 V 3.465 V 3.290 V 3.510 V

3.5 V 35 3.435 V 3.565 V 3.385 V 3.615 V

3.6 V 36 3.535 V 3.665 V 3.485 V 3.720 V

3.7 V 37 3.630 V 3.770 V 3.580 V 3.820 V

3.8 V 38 3.725 V 3.875 V 3.675 V 3.925 V

3.9 V 39 3.825 V 3.975 V 3.770 V 4.030 V

4.0 V 40 3.920 V 4.080 V 3.870 V 4.130 V

4.1 V 41 4.020 V 4.180 V 3.965 V 4.235 V

4.2 V 42 4.120 V 4.280 V 4.060 V 4.335 V

4.3 V 43 4.215 V 4.385 V 4.160 V 4.440 V

4.4 V 44 4.315 V 4.485 V 4.255 V 4.545 V

4.5 V 45 4.410 V 4.590 V 4.350 V 4.645 V

4.6 V 46 4.510 V 4.690 V 4.450 V 4.750 V

4.7 V 47 4.605 V 4.795 V 4.545 V 4.850 V

4.8 V 48 4.705 V 4.895 V 4.640 V 4.955 V

4.9 V 49 4.800 V 5.000 V 4.740 V 5.060 V

5.0 V 50 4.900 V 5.100 V 4.835 V 5.165 V

5.5 V 55 5.390 V 5.610 V

7.0 V 70 6.860 V 7.140 V

6.0 V 80 7.840 V 8.160 V 7.745 V 8.265 V

11.0 V 11 10.78 V 11.22 V 10.650 V 11.365 V

> 4.8 V.

OUT

OUT(TYP)

+ 1 V, I

= 30 mA, TA = 25 °C, unless otherwise specified.

OUT

Room Temp. Range (TA = 25 °C) Full Temp. Range (TA = -40 to +85 °C)

(Applies to "I" Rank Only)

OUT(MIN)

OUT(MAX)

OUT(MIN)

OUT(MAX)

January 1999 TOKO, Inc. Page 3

Page 4

TK732xx

ABSOLUTE MAXIMUM RATINGS (SPECIAL DEVICES) (Note 6)

Supply Voltage Range ............................................ 19 V

Power Dissipation (Note 1) ................................ 600 mW

Reverse Bias Voltage Range ..................................... 6 V

Noise Bypass Pin Terminal Voltage Range ............... 5 V

Control Pin Terminal Voltage Range........................ 14 V

TK73241MCLH, TK73242MCLH ELECTRICAL CHARACTERISTICS

Test conditions: VIN = V

LOBMYSRETEMARAPSNOITIDNOCTSETNIMPYTXAMSTINU

OUT(TYP)

+ 1 V, TA = 25 °C, unless otherwise specified.

Storage Temperature Range ................... -55 to +150 °C

Operating Temperature Range ...................-10 to +60 °C

Operating Voltage Range............................ 1.8 to 14.5 V

Junction Temperature ........................................... 150 °C

Lead Soldering Temperature (10 s) ...................... 235 °C

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Page 4 January 1999 TOKO, Inc.

Page 5

TK732xx

TK73241MCLH, TK73242MCLH ELECTRICAL CHARACTERISTICS CONT.

Note 1: Power dissipation is 600 mW when mounted as recommended. Derate at 4.8 mW/°C for operation above 25 °C. Note 2: Refer to “Definition of Terms.” Note 3: Ripple rejection and noise voltage are affected by the value and characteristics of the capacitor used. Note 4: This pin is used for Pulse Current Limit Mode. When selecting Continuous Current Limit Mode, this pin is connected to GND. Note 5: Not applicable for V Note 6: The voltage applied to any pin must be greater than -0.4 V. Gen. Note: Parameters with min. or max. values are 100% tested at TA = 25 °C.

TK73241MCLH, TK73242MCLH ELECTRICAL CHARACTERISTICS TABLE 2

Test Conditions: VIN = V

Output Voltage Voltage Code V

4.1 V 41 4.067 V 4.133 V 4.050 V 4.150 V

4.2 V 42 4.167 V 4.233 V 4.150 V 4.250 V

> 4.8 V.

OUT

OUT(TYP)

+ 1 V, I

= 30 mA, TA = 25 °C, unless otherwise specified.

OUT

Room Temp. Range (TA = 25 °C) Full Temp. Range (TA = -10 to +60 °C)

OUT(MIN)

OUT(MAX)

OUT(MIN)

OUT(MAX)

January 1999 TOKO, Inc. Page 5

Page 6

TK732xx

(

DIV)

(10

DIV)

(

DIV)

(

Note:Transistor: 2SB1115

CN = 0.1 µF CP = 0.1 µF CL = 4.7 µF RP = 330 k Continuous Current Limit Mode: I

(mA) = 100 mV / R

SET

Pulse Current Limit Mode: I

(mA) = 90 mV / R

SET

IPK

(Ω)

TEST CIRCUIT

IPK

EMITTER

CPC

TK732xx

TRANSISTOR

EXTERNAL

BASE

CONT

TA = 25 °C, external transistor is 2SB1115(NEC), unless otherwise specified.

LINE REGULATION 1

m 5

OUT

0 10 20

VIN (V)

QUIESCENT CURRENT

OUTPUT VOLTAGE

COLLECTOR

OUT

TYPICAL PERFORMANCE CHARACTERISTICS

LINE REGULATION 2

VS.

OUT

0 10 20

VIN (V)

DROPOUT VOLTAGE

OUTPUT VOLTAGE

VS.

5 m

OUT

0 500 1000

LOAD REGULATION

TYPICAL

OUT

(mA)

OUT

GROUND CURRENT

OUTPUT VOLTAGE

VS.

OUT

= 3.0 V

0 10 20

VIN (V)

= 5.0 V

-100

-200

DROP

-300

-400

0 500 1000

(mA)

OUT

2SB799

2SB1115

2SB1114

2SB1302

GND

0 500 1000

(mA)

OUT

Page 6 January 1999 TOKO, Inc.

Page 7

(

(A) I

(A)

(

OUT

(mV)

OUTPUT VOLTAGE VARIATION

VS.

TEMPERATURE

TA (°C)

-50 0 50 100

-10

-30

-50

OUT

TYPICAL

732xx

4.7 µF

OUT

CONT

RIPPLE REJECTION CIRCUIT

(V)

TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)

TA = 25 °C, external transistor is 2SB1115(NEC), unless otherwise specified.

TK732xx

CURRENT LIMIT DETECTOR VOLTAGE

VS. INPUT VOLTAGE

CONTINUOUS CURRENT

LIMIT MODE

100

∆

PULSE CURRENT

LIMIT MODE

0 5 10 15

VIN (V)

QUIESCENT CURRENT

INPUT VOLTAGE (OFF MODE)

1E-6

1E-9

VS.

BASE CURRENT DRIVE

INPUT VOLTAGE

100

0 5 10 15

VIN (V)

RIPPLE REJECTION

-20

-40

RR (dB)

-60

CN = 0.01 µF

CN = NONE

CN = 0.1 µF

-80

VS.

REVERSE BIAS CURRENT

(VIN = 0 TO 6 V)

1E-6

REV

1E-9

VIN = 0 V

VIN = 6 V

VIN = 4 V

VIN = 2 V

1E-12

0 5 10

(V)

REV

1E-12

0 10 20

VIN (V)

CONTROL CURRENT

TEMPERATURE

CONT

= 2 V

CONT

-50 0 50 100 TA (°C)

January 1999 TOKO, Inc. Page 7

-100

0.01 0.1 1 10 100 f (kHz)

VS.

CONTROL VOLTAGE (OUTPUT ON

POINT) VS. TEMPERATURE

CONT

= 5 V

2.0

1.0

CONT

= 0 Ω

-50 0 50 100

TA (°C)

Page 8

TK732xx

(V)

OUT

ON/OFF STEP RESPONSE

TIME (µs)

0 10 20 30

CL = 4.7 µF

CN = NONE

ON/OFF CONTROL

(200

DIV)

(20

DIV)

TYPICAL PERFORMANCE CHARACTERISTICS (CONT.)

TA = 25 °C, external transistor is 2SB1115(NEC), unless otherwise specified.

CONTROL PIN VOLTAGE

CONTROL CURRENT

CONT

-50 0 50 100 I

CONT

LOAD CURRENT STEP RESPONSE

= 0 TO 300 mA

OUT

CL = 47 OR 100 µF

CL = 10 µF

CL = 4.7 µF

CONT

(µA)

CL = 22 µF

OUT

= 100 k

CONT

= 0 k

= 200 k

ON/OFF TRANSIENT

5000

CL = 100 µF

1000

RISE TIME (µs)

OUT

CL = 4.7 µF

CL = 22 µF

100

0.001 0.01 0.1 10

LINE CURRENT STEP RESPONSE

OUT

= 50 mA

CL = 4.7 µF OR 10 µF

CN (µF)

+ 2 V

= NONE

= 0.1 µF

OUT

+ 1 V

0 5 10 15 20

Page 8 January 1999 TOKO, Inc.

TIME (µs)

Page 9

DEFINITION AND EXPLANATION OF TECHNICAL TERMS

TK732xx

OUTPUT VOLTAGE (V

The output voltage is specified with VIN = (V and I

= 30 mA.

OUT

DROPOUT VOLTAGE (V

OUT

)

DROP

OUT(TYP)

+ 1 V)

)

The dropout voltage is the difference between the input voltage and the output voltage at which point the regulator starts to fall out of regulation. Below this value, the output voltage will fall as the input voltage is reduced. It is dependent upon the load current, the external transistor and the junction temperature.

BASE CONTROL CURRENT (I

BASE

)

The base control current is the drive current for the base of the external transistor.

OUTPUT CURRENT (I

OUT

)

The output current depends on the characteristics of the external transistor and current limit setting.

LINE REGULATION (Line Reg)

RIPPLE REJECTION RATIO (RR)

Ripple rejection is the ability of the regulator to attenuate the ripple content of the input voltage at the output. It is specified with 100 mVrms, 400 Hz superimposed on the input voltage, where VIN = V

OUT(TYP)

+ 1.5 V. The output decoupling capacitor is set to 10 µF, the noise bypass capacitor is set to 0.1 µF, and the load current is set to 30 mA. Ripple rejection is the ratio of the ripple content of the output vs. the input and is expressed in dB.

STANDBY CURRENT (I

STBY

)

Standby current is the current which flows into the regulator when the output is turned off by the control function (V

= 0 V). It is measured with VIN = 8 V (9 V for the

CONT

8 V output device).

REMOTE SENSING (V

The V

pin is the output voltage sensing pin. If the

SENSE

)

voltage drop to the load caused by the PCB etch resistance cannot be disregarded, the voltage drop can be compensated by connecting the V

pin as shown

SENSE

below.

Line regulation is the ability of the regulator to maintain a constant output voltage as the input voltage changes. The line regulation is specified as the input voltage is changed from VIN = V

OUT(TYP)

+ 1 V to VIN = V

OUT(TYP)

+ 6 V.

LOAD REGULATION (Load Reg)

Load regulation is the ability of the regulator to maintain a constant output voltage as the load current changes. It is a pulsed measurement to minimize temperature effects. Load regulation depends on the external transistor.

QUIESCENT CURRENT (IQ)

The quiescent current is the current which flows through the ground terminal under no load conditions (I

OUT

= 0 mA)

and excludes the control pin current.

GROUND CURRENT (I

GND

)

Ground current is the current which flows through the ground pin(s). It is defined as I

- I

, excluding control

OUT

current.

EXTERNAL

TRANSISTOR

EMITTER BASE

IPK

The length of the V (11.8 in.) maximum.

COLLECTOR

OUT

TK732XX

etch should be limited to 30 cm

SENSE

January 1999 TOKO, Inc. Page 9

Page 10

TK732xx

DEFINITION AND EXPLANATION OF TECHNICAL TERMS (CONT.)

SENSOR CIRCUITS

Overcurrent Sensor

The overcurrent sensor protects the device if the output is shorted to ground.

Thermal Sensor

The thermal sensor protects the device if the junction temperature exceeds the safe value (Tj = 150 °C). This temperature rise can be caused by extreme heat, excessive power dissipation caused by large output voltage drops, or excessive output current. The regulator will shut off when the temperature exceeds the safe value. As the junction temperature decreases, the regulator will begin to operate again. Under sustained fault conditions, the regulator output will oscillate as the device turns off then resets. Damage may occur to the device under extreme fault conditions.

Reverse Voltage Protection

Reverse voltage protection prevents damage due to the output voltage being higher than the input voltage. This fault condition can occur when the output capacitor remains charged and the input is reduced to zero, or when an external voltage higher than the input voltage is applied to the output side.

deliberately increase the output current (or raise the input voltage) until the thermal protection circuit is activated. Calculate the power dissipation of the device by subtracting the output power from the input power. These measurements should allow for the ambient temperature of the PCB. The value obtained from PD /(150 °C - TA) is the derating factor. The PCB mounting pad should provide maximum thermal conductivity in order to maintain low device temperatures. As a general rule, the lower the temperature, the better the reliability of the device. The thermal resistance when mounted is expressed as follows:

Tj = 0jA x PD + T

For Toko ICs, the internal limit for junction temperature is 150 °C. If the ambient temperature (TA) is 25 °C, then:

150 °C = 0jA x PD + 25 °C 0jA = 125 °C / P

PD is the value when the thermal sensor is activated. A simple way to determine PD is to calculate VIN x IIN when the output side is shorted. Input current gradually falls as temperature rises. You should use the value when thermal equilibrium is reached.

PACKAGE POWER DISSIPATION (PD)

The range of usable currents can also be found from the graph below.

This is the power dissipation level at which the thermal sensor is activated. The IC contains an internal thermal sensor which monitors the junction temperature. When the

(mW)

junction temperature exceeds the monitor threshold of 150 °C, the IC is shut down. The junction temperature rises as the difference between the input power (VIN x IIN) and the output power (V

OUT

x I

) increases. The rate of

OUT

temperature rise is greatly affected by the mounting pad

configuration on the PCB, the board material, and the ambient temperature. When the IC mounting has good thermal conductivity, the junction temperature will be low

25 50 75 150

TA (°C)

even if the power dissipation is great. When mounted on the recommended mounting pad, the power dissipation of

Procedure:

the SOT-23L-8 is increased to 600 mW. For operation at ambient temperatures over 25 °C, the power dissipation of the SOT-23L-8 device should be derated at 4.8 mW/°C. To determine the power dissipation for shutdown when mounted, attach the device on the actual PCB and

1) Find P

2) PD1 is taken to be PD x (Note: It is not necessary to connect

a ceramic capacitor in parallel with an aluminum or tantalum output capacitor. (~0.8 - 0.9)

Page 10 January 1999 TOKO, Inc.

Page 11

TK732xx

DEFINITIONS AND TERMS (CONT.)

3) Plot PD1 against 25 °C

4) Connect P with a straight line.

5) In design, take a vertical line from the maximum operating temperature (e.g., 75 °C) to the derating curve.

6) Read off the value of PD against the point at which the vertical line intersects the derating curve. This is taken as the maximum power dissipation, DPD.

The maximum operating current is:

OUT

(mW)

to the point corresponding to the 150 °C

= (D

750

600

450

300

150

/ (V

IN(MAX) - VOUT

MOUNTED AS

SHOWN

FREE AIR

)

APPLICATION INFORMATION

INPUT-OUTPUT CAPACITORS

The output capacitor is necessary for stable operation. The regulator may oscillate if the output capacitor is too small or missing. The output capacitor size is determined by load, transient response and external transistor used. Evaluation in the circuit is recommended to ensure performance requirements are satisfied. A minimum of 4.7 µF is necessary for stability, with twice that value recommended. The minimum recommended input capacitor is 1 µF. Problems do not occur with larger values of capacitance. However, extremely low ESR may result in unstable operation. Thus, the use of large value ceramic capacitors is not recommended on the output.

BOARD LAYOUT

GND

CONTROL

0 50 100 150

TA (°C)

SOT-23L-8 POWER DISSIPATION CURVE

GND

SOT-23L-8 BOARD LAYOUT

OUT

IPK

January 1999 TOKO, Inc. Page 11

Page 12

TK732xx

APPLICATION INFORMATION (CONT.)

PULSE CURRENT LIMIT MODE

330 k

EMITTER

TK732xx

EXTERNAL

TRANSISTOR

BASE

COLLECTOR

CONT

GND

OUT

IPK

The equation for the pulse output current limit is as follows:

OUT

(mA) = 90 (mV) / R

SET

OUT

IPK

(Ω)

During the initial turn-on, charge (surge) current flows to the output capacitor. This IC has a possibility for the current limit to operate and to turn off the output by the charge current of the output capacitor. Therefore, the relationship between CL and CP is set as shown in the graph below:

CONTINUOUS CURRENT LIMIT MODE

IPK

EMITTER

TK732xx

EXTERNAL

TRANSISTOR

In the continuous current limit mode, the C

CONT

BASE

COLLECTOR

CONT

PULSE

GND

OUT

pin (pin 3) is directly connected to ground. The output current limit is set by R

according to the following equation:

IPK

(mA) = 100 (mV) / R

SET

IPK

(Ω)

If the continuous current limit mode is also used for output short circuit protection, the I

value is set 50% to 100%

SET

more than the maximum operating current. The current transistor is selected from the I voltage drops when the output current exceeds the I

value. The output

SET

value. However, the output voltage returns to normal once the output current decreases below the I

SET

value.

1000

100

(µF)

STABLE REGION

100.10.01

CP (µF)

Page 12 January 1999 TOKO, Inc.

Page 13

TK732xx

APPLICATION INFORMATION (CONT.)

EXTERNAL PNP POWER TRANSISTOR

This IC can use any kind of external transistor. The external transistor selection is a function of the load current, Hfe and power dissipation. See following chart:

LOAD CURRENT RECOMMENDED EXTERNAL TRANSISTOR RECOMMENDED R

0 ~ 180 mA 2SB624, 2SB1115, 2SB799 (NEC), 2SB970 (Matushita) 0.33 ~ 0.39 0 ~ 300 mA 2SB1115, 2SB799 (NEC) 0.22 ~ 0.27

0 ~ 500 mA

2SB1114, 2SB1115 (NEC), 2SB1302 (Sanyo), 2SA1203, 2SA1213, 2SA1734 (Toshiba)

0.12 ~ 0.15

0 ~ 1 A 2SA1242, 2SA1736 (Toshiba), 2SB1302, 2SA1896 (Sanyo) 0.056 ~ 0.068 0 ~ 2 A 2SA1451, 2SA1242 (Toshiba) 0.033 ~ 0.039 0 ~ 3 A 2SA1451 (Toshiba), 2SA1645 (NEC) 0.022 ~ 0.027 0 ~ 4 A 2SA1451 (Toshiba), 2SB904 (Sanyo), 2SA1645 (NEC) 0.012 ~ 0.015

HIGH-SIDE SWITCHING

DROP

VOLTAGE

REGULATOR

OUT

IPK

(Ω)

ON/OFF

CONTROL

High-side switching should not be implemented by an external transistor as shown above. This results in additional voltage drop and loss of accuracy.

µ PRO

TK732xx

CONT

OUT

The high output voltage accuracy and low dropout voltage are maintained when the IC is turned ON/OFF by using the control pin as illustrated above.

January 1999 TOKO, Inc. Page 13

Page 14

TK732xx

APPLICATION INFORMATION (CONT.)

VOLTAGE BACKUP OPERATION (HOLDUP TIME)

OUT

VOLTAGE

DETECTOR

CONT

OFF

732xx

µ PRO

RESET

CL becomes the backup power supply when the microprocessor is reset with the voltage detector IC simultaneously with turning OFF the TK732xx. CL provides the holdup time necessary to do an orderly shutdown of the microprocessor.

PARALLEL ON/OFF CONTROL OPERATION

OUTPUT VOLTAGE ADJUST

OUT

ADJ

1000 pF

CONT

TK732xx

SENSE

When a highly accurate output voltage is necessary, the output can be adjusted. As shown above, higher output resolution can be achieved by putting a resistor (R the V

pin in parallel with a 1000 pF capacitor. A value

SENSE

ADJ

) in

of 2 K provides an adjustment of 50 mV typically. Note: using this technique, the output voltage can only be adjusted higher.

BATTERY CHARGER

ON/OFF

CONTROL

TK732xx

TK11230B

TK11220B

5 V 5 A

3 V

100 mA

2 V

100 mA

The figure above illustrates multiple regulators being controlled by a single ON/OFF control signal. The series resistor R is put in the input line of the low output voltage regulator in order to prevent overdissipation. The voltage dropped across the resistor reduces the large input-tooutput voltage across the regulator, reducing the power dissipation in the device.

CONT

IPK

CURRENT

LIMIT

SENSING

EMITTER

TK732XX

EXTERNAL

TRANSISTOR

BASE

COLLECTOR

Continuous Current Limit Mode:

(mA) = 100 (mV) / R

SET

CONT

VOLTAGE DETECTOR

CIRCUIT

LOAD

MICROPROCESSOR

SENSE

BATTERY

ADJ

REMOTE

SENSING

OUT

(Ω)

IPK

Page 14 January 1999 TOKO, Inc.

Page 15

APPLICATION INFORMATION (CONT.)

(Continuous Current Limit Mode) is set to the desired

SET

charging current.

CHARGING CHARACTERISTICS

FINISH CHARGE

4.1 V

OUT

SET CHARGING CURRENT

OUT

TK732xx

circuit condition, Tr1 is turned “off.” This converts the circuit into the pulse current limit mode of operation, reducing the power dissipation in the pass transistor. The transition between the continuous and pulse current limit modes can be controlled by adjusting the operating point of Tr1 by the value of resistor R.

LITHIUM ION BATTERY CHARGER WITH OVERDISSIPATION PROTECTION OF EXTERNAL TRANSISTOR (SHORT CIRCUIT MODE)

(RECOMMENDED WITH TK732xxMCLH)

IPK

TK732xx

EMITTER

EXTERNAL

TRANSISTOR

COLLECTOR

BASE

CONT

BATTERY

LOAD

OUT

During normal operation, Tr1 is turned ON, connecting pin 3 (C

) to ground. This provides the continuous current

PULSE

limit mode for normal operating conditions. During a short

January 1999 TOKO, Inc. Page 15

Page 16

TK732xx

PACKAGE OUTLINE

SOT-23L-8

Product Code

Dimensions are shown in millimeters Tolerance: x.x = ± 0.2 mm (unless otherwise specified)

Marking Information

Product Code C

Voltage Code

0.45

marking

Voltage Code

0.8

+0.3

- 0.1

3.5

(3.4)

0.3

0.1

1.4max

Çl

1.2

0 - 0.1

+0.15

- 0.15

(0.3)

0.15

1.0

Recommended Mount Pad

3.3

3.0 1

0.8

2.2

15 max

+ 0.3

0.4

TK73220 20 TK73221 21 TK73222 22 TK73223 23 TK73224 24 TK73225 25 TK73226 26 TK73227 27 TK73228 28 TK73229 29 TK73230 30 TK73231 31 TK73232 32 TK73233 33 TK73234 34 TK73235 35 TK73236 36 TK73237 37 TK73238 38 TK73239 39 TK73240 40 TK73241 41 TK73242 42 TK73243 43 TK73244 44 TK73245 45 TK73246 46 TK73247 47 TK73248 48 TK73249 49 TK73250 50 TK73255 55 TK73270 70 TK73280 80 TK73211 11

Toko America, Inc. Headquarters 1250 Feehanville Drive, Mount Prospect, Illinois 60056 Tel: (847) 297-0070 Fax: (847) 699-7864

TOKO AMERICA REGIONAL OFFICES

Midwest Regional Office Toko America, Inc. 1250 Feehanville Drive Mount Prospect, IL 60056 Tel: (847) 297-0070 Fax: (847) 699-7864

Western Regional Office Toko America, Inc. 2480 North First Street , Suite 260 San Jose, CA 95131 Tel: (408) 432-8281 Fax: (408) 943-9790

Eastern Regional Office Toko America, Inc. 107 Mill Plain Road Danbury, CT 06811 Tel: (203) 748-6871 Fax: (203) 797-1223

Semiconductor Technical Support Toko Design Center 4755 Forge Road Colorado Springs, CO 80907 Tel: (719) 528-2200 Fax: (719) 528-2375

Visit our Internet site at http://www.tokoam.com

The information furnished by TOKO, Inc. is believed to be accurate and reliable. However, TOKO reserves the right to make changes or improvements in the design, specification or manufacture of its products without further notice. TOKO does not assume any liability arising from the application or use of any product or circuit described herein, nor for any infringements of patents or other rights of third parties which may result from the use of its products. No license is granted by implication or otherwise under any patent or patent rights of TOKO, Inc.

Page 16 January 1999 TOKO, Inc.

IC-xxx-TK732xx

0798O0.0K

Printed in the USA