Texas Instruments TPS70845, TPS70848, TPS70851, TPS70858, TPS70802 Datasheet

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TPS70845, TPS70848

TPS70851, TPS70858

TPS70802

www.ti.com

SLVS301D–JUNE 2000–REVISED DECEMBER 2007

DUAL-OUTPUT, LOW DROPOUT VOLTAGE REGULATORS

WITH INTEGRATED SVS FOR SPLIT VOLTAGE SYSTEMS

FEATURES

Dual Output Voltages for Split-Supply Applications

Independent Enable Functions (See Part Number TPS707xx for Sequenced Outputs)

Output Current Range of 250 mA on Regulator 1 and 125 mA on Regulator 2

Voltage Options: 3.3-V/2.5-V, 3.3-V/1.8-V, 3.3-V/1.5-V, 3.3-V/1.2-V, and Dual Adjustable Outputs

Open Drain Power-On Reset with 120-ms Delay

Open Drain Power Good for Regulator 1 and Regulator 2

Ultralow 190-μA (typ) Quiescent Current

1-μA Input Current During Standby

Low Noise: 65 μVRMS Without Bypass

Capacitor

Quick Output Capacitor Discharge Feature

One Manual Reset Input

2% Accuracy Over Load and Temperature

Undervoltage Lockout (UVLO) Feature

20-Pin PowerPAD™ TSSOP Package

Thermal Shutdown Protection

DESCRIPTION

The TPS708xx is a low dropout voltage regulator with integrated SVS (RESET, POR, or power on reset) and power good (PG) functions. These devices are capable of supplying 250 mA and 125 mA by regulator 1 and regulator 2 respectively. Quiescent current is typically 190 μA at full load. Differentiated features, such as accuracy, fast transient response, SVS supervisory circuit (power on reset), manual reset input, and independent enable functions provide a complete system solution.

PWP PACKAGE

(TOP VIEW)

 

 

NC

 

 

1

20

 

 

NC

 

 

 

 

 

 

 

V

IN1

 

 

2

19

 

 

V

OUT1

 

 

 

 

 

V

IN1

 

 

3

18

 

 

V

OUT1

 

 

 

 

 

 

 

 

 

 

4

17

 

 

VSENSE1/FB1

 

MR

 

 

 

 

 

 

5

16

 

 

EN1

 

 

 

 

PG1

 

6

15

 

 

 

 

 

 

 

 

 

PG2

EN2

 

 

 

 

 

 

 

 

 

 

 

 

 

 

7

14

 

 

VSENSE2/FB2

RESET

 

 

 

 

 

 

 

 

 

GND

 

 

8

13

 

 

VOUT2

 

 

 

 

 

 

 

 

 

 

 

 

V

IN2

 

 

9

12

 

 

V

OUT2

 

 

 

 

V

 

10

11

 

 

 

IN2

 

 

 

 

NC

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

NC: No internal connection

 

 

 

 

 

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.

PowerPAD is a trademark of Texas Instruments.

All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Copyright © 2000–2007, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

 

necessarily include testing of all parameters.

 

TPS70845, TPS70848

TPS70851, TPS70858

TPS70802

www.ti.com

SLVS301D–JUNE 2000–REVISED DECEMBER 2007

 

 

TPS70851PWP

 

 

 

 

 

 

VIN1

VOUT1

 

 

3.3 V

I/O

 

5V

 

 

 

 

 

0.1 µF

 

VSENSE1

 

10 µF

 

 

 

 

 

 

250 kΩ

 

 

 

 

 

 

 

 

 

 

 

 

PG1

 

PG1

250 kΩ

 

 

 

 

MR

 

 

 

 

 

VIN2

MR

>2 V

 

 

 

 

 

 

 

 

 

 

<0.7 V

250 kΩ

 

 

 

 

 

 

 

 

0.1 µF

 

RESET

 

 

 

RESET

 

 

 

 

 

 

>2 V

EN1

EN1

PG2

PG2

 

 

 

 

<0.7 V

 

 

 

 

 

 

 

 

 

 

>2 V

EN2

EN2

VSENSE2

 

 

 

 

 

<0.7 V

 

 

 

 

 

 

 

 

VOUT2

 

 

1.8 V

Core

 

 

 

 

10 µF

 

 

 

 

 

 

 

 

DESCRIPTION (CONTINUED)

The TPS708xx family of voltage regulators offers very low dropout voltage and dual outputs. These devices have extremely low noise output performance without using any added filter bypass capacitors and are designed to have a fast transient response and be stable with 10-μF low ESR capacitors.

These devices have fixed 3.3-V/2.5-V, 3.3-V/1.8-V, 3.3-V/1.5-V, 3.3-V/1.2-V, and adjustable voltage options. Regulator 1 can support up to 250 mA, and regulator 2 can support up to 125 mA. Separate voltage inputs allow the designer to configure the source power.

Because the PMOS device behaves as a low-value resistor, the dropout voltage is very low (typically 170 mV on regulator 1) and is directly proportional to the output current. Additionally, since the PMOS pass element is a voltage-driven device, the quiescent current is very low and independent of output loading (maximum of 230 μA over the full range of output current and full range of temperature). This LDO family also features a sleep mode; applying a high signal to EN1 or EN2 (enable) shuts down regulator 1 or regulator 2, respectively. When a high signal is applied to both EN1 and EN2, both regulators enter sleep mode, thereby reducing the input current to 2 μA at TJ = +25°C.

For each regulator, there is an internal discharge transistor to discharge the output capacitor when the regulator is turned off (disabled).

The PG1 pin reports the voltage condition at VOUT1. The PG1 pin can be used to implement a SVS (RESET, POR, or power on reset) for the circuitry supplied by regulator 1. The PG2 pin reports the voltage conditions at

VOUT2. The PG2 pin can be used to implement a SVS (power on reset) for the circuitry supplied by regulator 2.

The TPS708xx features a RESET (SVS, POR, or power on reset). RESET output initiates a reset in the event of an undervoltage condition. RESET also indicates the status of the manual reset pin (MR). When MR is in the

logic high state, RESET goes to a high impedance state after a 120-ms delay. To monitor VOUT1, the PG1 output pin can be connected to MR. To monitor VOUT2, the PG2 output pin can be connected to MR.

The device has an undervoltage lockout UVLO circuit that prevents the internal regulators from turning on until VIN1 reaches 2.5V.

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TPS70845, TPS70848 TPS70851, TPS70858

TPS70802

www.ti.com

SLVS301D–JUNE 2000–REVISED DECEMBER 2007

This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.

ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.

ORDERING INFORMATION(1)

 

VOLTAGE (V)(2)

PACKAGE-

SPECIFIED

 

 

 

 

 

LEAD

TEMPERATURE

ORDERING

TRANSPORT

PRODUCT

VOUT1

VOUT2

(DESIGNATOR)

RANGE (TJ)

NUMBER

MEDIA, QUANTITY

TPS70802

Adjustable

Adjustable

HTSSOP-20 (PWP)

–40°C to +125°C

TPS70802PWP

Tube, 70

TPS70802PWPR

Tape and Reel, 2000

 

 

 

 

 

TPS70845

3.3 V

1.2 V

HTSSOP-20 (PWP)

–40°C to +125°C

TPS70845PWP

Tube, 70

TPS70845PWPR

Tape and Reel, 2000

 

 

 

 

 

TPS70848

3.3 V

1.5 V

HTSSOP-20 (PWP)

–40°C to +125°C

TPS70848PWP

Tube, 70

TPS70848PWPR

Tape and Reel, 2000

 

 

 

 

 

TPS70851

3.3 V

1.8 V

HTSSOP-20 (PWP)

–40°C to +125°C

TPS70851PWP

Tube, 70

TPS70851PWPR

Tape and Reel, 2000

 

 

 

 

 

TPS70858

3.3 V

2.5 V

HTSSOP-20 (PWP)

–40°C to +125°C

TPS70858PWP

Tube, 70

TPS70858PWPR

Tape and Reel, 2000

 

 

 

 

 

(1)For the most current package and ordering information see the Package Option Addendum located at the end of this document, or see the TI web site at www.ti.com.

(2)For fixed 1.20 V operation, tie FB to OUT.

ABSOLUTE MAXIMUM RATINGS(1)

Over operating free-air temperature range (unless otherwise noted).

 

TPS708xx

UNIT

(2)

–0.3 to +7

V

Input voltage range: VIN1, VIN2

Voltage range at EN1, EN2

–0.3 to +7

V

Output voltage range (VOUT1, VSENSE1)

5.5

V

Output voltage range (VOUT2, VSENSE2)

5.5

V

Maximum RESET, PG1, PG2 voltage

7

V

Maximum MR voltage

VIN1

V

Peak output current

Internally limited

Continuous total power dissipation

See Dissipation Ratings Table

Operating virtual junction temperature range, TJ

–40 to +150

°C

Storage temperature range, Tstg

–65 to +150

°C

ESD rating, HBM

2

kV

(1)Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under recommended operating conditions is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.

(2)All voltages are tied to network ground.

Copyright © 2000–2007, Texas Instruments Incorporated

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TPS70851, TPS70858

TPS70802

 

 

 

 

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SLVS301D–JUNE 2000–REVISED DECEMBER 2007

 

 

 

 

DISSIPATION RATINGS

 

 

 

 

PACKAGE

AIR FLOW (CFM)

TA ≤ +25°C

DERATING

TA = +70°C

TA = +85°C

FACTOR

 

 

 

 

 

PWP(1)

0

3.067 W

30.67 mW/°C

1.687 W

1.227 W

250

4.115 W

41.15 mW/°C

2.265 W

1.646 W

 

(1)This parameter is measured with the recommended copper heat sink pattern on a 4-layer PCB, 1 oz. copper on a 4-in by 4-in ground layer. Simultaneous and continuous operation of both regulator outputs at full load may exceed the power dissipation rating of the PWP package. For more information, refer to TI technical brief SLMA002.

RECOMMENDED OPERATING CONDITIONS

Over operating temperature range (unless otherwise noted).

 

MIN

MAX

UNIT

Input voltage, V (1) (regulator 1 and 2)

2.7

6

V

I

 

 

 

Output current, IO (regulator 1)

0

500

mA

Output current, IO (regulator 2)

0

250

mA

Output voltage range (for adjustable option)

1.22

5.5

V

Operating virtual junction temperature, TJ

–40

+125

°C

(1)To calculate the minimum input voltage for maximum output current, use the following equation: VI(min) = VO(max) + VDO(max load).

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Copyright © 2000–2007, Texas Instruments Incorporated

TPS70845, TPS70848 TPS70851, TPS70858

TPS70802

www.ti.com

SLVS301D–JUNE 2000–REVISED DECEMBER 2007

ELECTRICAL CHARACTERISTICS

Over recommended operating junction temperature range (TJ = –40°C to +125°C), VIN1 or VIN2 = VOUT(nom) + 1 V, IO = 1 mA, EN = 0 V, and COUT = 33 μF (unless otherwise noted).

 

PARAMETER

 

 

Reference

 

 

voltage

 

 

1.2 V Output

VO

Output

1.5 V Output

 

voltage (1),(2)

 

1.8 V Output

2.5 V Output

3.3 V Output

Quiescent current (GND current) for

regulator 1 and regulator 2, EN1 = EN2 = 0 V(1)

Output voltage line regulation (∆VO/VO) for regulator 1 and regulator 2 (3)

Load regulation for VOUT 1 and VOUT2

Vn

Output noise

Regulator 1

voltage

Regulator 2

 

Regulator 1

Output current limit

Regulator 2

Thermal shutdown junction temperature

II

Standby

Regulator 1

(standby)

current

Regulator 2

 

Power-

Regulator 1

PSRR

supply ripple

 

 

rejection

Regulator 2

UVLO threshold

RESET Terminal

TEST CONDITIONS

MIN

TYP

MAX UNIT

2.7 V < VIN < 6 V,

TJ = +25°C

2.7V < VIN < 6 V,

2.7V < VIN < 6 V,

2.7V < VIN < 6 V,

2.7V < VIN < 6 V,

2.7V < VIN < 6 V,

2.8V < VIN < 6 V,

2.8V < VIN < 6 V,

3.5V < VIN < 6 V,

3.5V < VIN < 6 V,

4.3V < VIN < 6 V,

4.3 V < VIN < 6 V,

See (2)

See (2)

VO + 1 V < VIN ≤ 6 V,

VO + 1 V < VIN ≤ 6 V

TJ = +25°C

BW = 300 Hz to 50 kHz,

VOUT = 0 V

EN1 = VIN, EN2 = VIN

EN1 = VIN, EN2 = VIN

f = 1 kHz, COUT = 33 μF,

IOUT1 = 250 mA

f = 1 kHz, COUT = 33 μF,

IOUT2 = 125 mA

FB connected to VO

 

1.22

 

 

FB connected to VO

1.196

 

1.244

 

TJ = +25°C

 

1.2

 

 

 

1.176

 

1.224

 

TJ = +25°C

 

1.5

 

 

 

1.47

 

1.53

V

TJ = +25°C

 

1.8

 

 

 

1.764

 

1.836

 

TJ = +25°C

 

2.5

 

 

 

2.45

 

2.55

 

TJ = +25°C

 

3.3

 

 

 

3.234

 

3.366

 

TJ = +25°C

 

190

 

μA

 

 

 

230

 

 

 

 

TJ = +25°C(1)

 

0.01

 

%V

(1)

 

 

0.1

 

 

 

 

 

1

 

mV

CO = 33 μF, TJ = +25°C

 

65

 

μVRMS

 

65

 

 

 

 

 

 

 

1.6

1.9

A

 

 

0.750

1

 

 

 

 

 

+150

 

°C

TJ = +25°C

 

 

2

μA

 

 

 

6

 

 

 

 

TJ = +25°C(1)

 

60

 

dB

TJ = +25°C(1)

 

 

 

 

50

 

 

 

2.4

 

2.65

V

Minimum input voltage for valid RESET

I(RESET) = 300 μA,

V(RESET) ≤ 0.8 V

 

1.0

1.3

V

t(RESET)

RESET pulse duration

 

80

120

160

ms

Output low voltage

VIN = 3.5 V,

I(RESET) = 1 mA

 

0.15

0.4

V

Leakage current

V(RESET) = 6 V

 

 

 

1

μA

(1)Minimum input operating voltage is 2.7 V or VO(typ) + 1 V, whichever is greater. Maximum input voltage = 6 V, minimum output current = 1 mA.

(2)IO = 1 mA to 250 mA for Regulator 1 and 1 mA to 125 mA for Regulator 2.

Line regulation (mV) = (%/V) x Vo

(VImax − 2.7)

x 1000

 

 

 

(3) If VO < 1.8 V then VImax = 6 V, VImin = 2.7 V:

100

 

 

 

 

 

[ VImax − (Vo

+ 1) ]

Line regulation (mV) = (%/V) x Vo

 

 

 

x 1000

 

 

 

If VO > 2.5 V then VImax = 6 V, VImin = VO + 1 V:

100

 

 

Copyright © 2000–2007, Texas Instruments Incorporated

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TPS70851, TPS70858

TPS70802

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SLVS301D–JUNE 2000–REVISED DECEMBER 2007

ELECTRICAL CHARACTERISTICS (continued)

Over recommended operating junction temperature range (TJ = –40°C to +125°C), VIN1 or VIN2 = VOUT(nom) + 1 V, IO = 1 mA, EN = 0 V, and COUT = 33 μF (unless otherwise noted).

PARAMETER

TEST CONDITIONS

MIN

TYP

MAX

UNIT

PG1/PG2 Terminal

 

 

 

 

 

 

Minimum input voltage for valid PGx

I(PGx) = 300 μA,

V(PGx) ≤ 0.8 V

 

1.0

1.3

V

Trip threshold voltage

VO decreasing

 

92

95

98

%VOUT

Hysteresis voltage

Measured at VO

 

 

0.5

 

%VOUT

tr(PGx)

Rising edge deglitch

 

 

30

 

μs

Output low voltage

VIN = 2.7V,

I(PGx) = 1 mA

 

0.15

0.4

V

Leakage current

V(PGx) = 6V

 

 

 

1

μA

EN1/EN2 Terminal

 

 

 

 

 

 

High-level ENx input voltage

 

 

2

 

 

V

Low-level ENx input voltage

 

 

 

 

0.7

V

Input current (ENx)

 

 

–1

 

1

μA

MR Terminal

 

 

 

 

 

 

High-level input voltage

 

 

2

 

 

V

Low-level input voltage

 

 

 

 

0.7

V

Falling edge delay

Measured at VO

 

 

140

 

μs

Pull-up current source

 

 

 

6

 

μA

VOUT1 Terminal

 

 

 

 

 

 

Dropout voltage(4)

IO = 250 mA, VIN1 = 3.2 V

TJ = +25°C

 

83

 

mV

IO = 250 mA, VIN1 = 3.2 V

 

 

 

140

 

 

 

 

 

Peak output current

2 ms pulse width

 

 

750

 

mA

Discharge transistor current

VOUT1 = 1.5 V

 

 

7.5

 

mA

VOUT2 Terminal

 

 

 

 

 

 

Peak output current

2 ms pulse width

 

 

375

 

mA

Discharge transistor current

VOUT2 = 1.5 V

 

 

7.5

 

mA

FB Terminal

 

 

 

 

 

 

Input current: TPS70802

FB = 1.8 V

 

 

1

 

μA

(4)Input voltage (VIN1 or VIN2) = VO(typ) – 100 mV. For 1.5-V, 1.8-V, and 2.5-V regulators, the dropout voltage is limited by input voltage range. The 3.3-V regulator input is set to 3.2 V to perform this test.

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Texas Instruments TPS70845, TPS70848, TPS70851, TPS70858, TPS70802 Datasheet

 

 

 

 

 

 

 

TPS70845, TPS70848

 

 

 

 

 

 

 

TPS70851, TPS70858

www.ti.com

 

 

 

 

 

 

TPS70802

 

 

 

 

 

 

SLVS301D–JUNE 2000–REVISED DECEMBER 2007

 

 

 

DEVICE INFORMATION

 

 

 

 

 

 

Fixed Voltage Version

 

 

 

VIN1 (2 Pins)

 

 

 

 

 

 

VOUT1 (2 Pins)

 

 

 

 

 

 

 

 

 

UVLO

 

 

 

 

 

 

Comp

 

Current

 

 

10 kΩ

 

 

 

Sense

 

 

 

 

 

 

 

 

ENA_1

VSENSE1

 

 

 

 

 

 

2.5 V

+

 

 

 

 

 

(see Note A)

 

 

 

 

 

 

 

 

 

 

 

+

ENA_1

 

GND

Thermal

Reference

Vref

 

 

FB1

 

 

Vref

 

 

 

 

Shutdown

 

 

 

 

 

 

 

 

 

 

 

PG1

VSENSE1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Rising Edge

 

 

 

 

 

 

 

 

 

 

0.95 x Vref

 

 

+

 

 

 

 

 

 

Deglitch

 

 

 

 

VIN1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PG1

Comp

 

 

 

 

 

 

 

MR

 

 

 

 

 

 

 

RESET

 

 

 

 

 

 

 

Falling Edge

 

 

 

ENA_1

 

 

 

Delay

 

 

EN1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PG2

PG2

 

 

 

 

 

 

Comp

 

 

 

 

 

VSENSE2

Rising Edge

 

 

 

 

 

0.95 x Vref

+

Deglitch

 

 

 

 

 

 

 

 

 

 

ENA_2

Vref

 

FB2

 

 

 

 

 

 

 

 

 

EN2

 

 

 

 

 

 

 

 

 

+

 

 

 

 

 

 

 

ENA_2

 

 

 

 

 

 

 

 

VSENSE2

 

 

 

 

Current

 

ENA_2

(see Note A)

 

 

 

 

 

 

 

 

 

 

 

Sense

 

 

10 kΩ

 

 

 

 

 

 

 

V

IN2

(2 Pins)

 

 

 

 

VOUT2 (2 Pins)

 

 

 

 

 

 

 

A.For most applications, VSENSE1 and VSENSE2 should be externally connected to VOUT1 and VOUT2, respectively, as close as possible to the device. For other implementations, refer to SENSE terminal connection discussion in the

Application Information section.

Copyright © 2000–2007, Texas Instruments Incorporated

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SLVS301D–JUNE 2000–REVISED DECEMBER 2007

Adjustable Voltage Version

VIN1 (2 Pins)

 

 

UVLO

 

 

 

 

 

 

 

Comp

 

Current

 

 

 

 

 

 

 

Sense

 

 

 

 

 

 

 

 

 

 

ENA_1

 

 

 

 

 

 

 

 

 

2.5 V

+

 

 

 

 

 

 

 

 

 

 

 

 

+

ENA_1

 

GND

Thermal

Reference

Vref

 

 

 

 

 

 

 

Vref

 

 

 

 

Shutdown

 

 

 

 

 

 

 

 

 

FB1

 

Rising Edge

 

 

 

 

 

 

 

 

 

 

 

 

 

0.95 x Vref

+

 

Deglitch

VIN1

 

 

 

 

 

 

 

 

 

 

 

PG1

 

 

 

 

 

 

 

 

Comp

 

 

 

 

 

 

 

 

 

 

 

Falling Edge

 

 

 

ENA_1

 

 

 

 

Delay

EN1

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

PG2

 

 

 

 

 

 

 

 

Comp

 

 

 

 

 

 

 

FB2

 

Rising Edge

 

 

 

 

 

 

 

 

 

 

 

 

 

0.95 x Vref

+

 

Deglitch

 

 

 

 

 

 

 

 

 

 

 

ENA_2

Vref

FB2

 

 

 

 

 

 

 

 

EN2

 

 

 

 

 

 

 

 

 

 

 

 

+

 

 

 

 

 

 

 

 

 

ENA_2

 

 

 

 

 

Current

ENA_2

 

 

 

 

 

 

Sense

 

 

 

 

VIN2 (2 Pins)

VOUT1 (2 Pins)

FB1 (see Note A)

PG1

MR

RESET

PG2

FB2 (see Note A)

VOUT2 (2 Pins)

A.For most applications, FB1 and FB2 should be externally connected to resistor dividers as close as possible to the device. For other implementations, refer to FB terminals connection discussion in the Application Information section.

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Copyright © 2000–2007, Texas Instruments Incorporated

TPS70845, TPS70848 TPS70851, TPS70858

TPS70802

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SLVS301D–JUNE 2000–REVISED DECEMBER 2007

RESET Timing Diagram

VUVLO

VRES (see Note A)

VIN1

VUVLO

VRES

t

MR Input

t

RESET Output

 

 

 

 

 

 

 

 

 

 

120 ms

 

 

120 ms

 

 

 

 

 

 

 

Output

 

 

 

 

 

 

 

 

Undefined

 

 

 

Delay

 

 

Delay

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Output

Undefined

t

NOTE A: VRES is the minimum input voltage for a valid RESET. The symbol VRES is not currently listed within EIA or JEDEC standards for semiconductor symbology.

PG1 Timing Diagram

VIN1

 

VUVLO

VUVLO

 

VPG1

V

 

PG

(see Note A)

 

 

t

VOUT1

VIT+

Threshold

(see Note B)

 

Voltage

 

VIT

(see Note B)

 

 

t

PG1 Output

PG1

 

 

 

Output

 

Output

Undefined

 

Undefined

 

 

t

NOTES A: VPG1 is the minimum input voltage for a valid PG. The symbol VPG1 is not currently listed within EIA or JEDEC

standards for semiconductor symbology.

 

B: VIT− trip voltage is typically 5% lower than the output voltage (95%VO). VIT− to VIT+ is the hysteresis voltage.

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TPS70845, TPS70848

TPS70851, TPS70858

TPS70802

SLVS301D–JUNE 2000–REVISED DECEMBER 2007

PG2 Timing Diagram (assuming VIN1 already powered up)

VIN2

VOUT2

Threshold

Voltage

PG2

Output

www.ti.com

t

VIT+ (see Note A)

VIT

(see Note A)

t

t

NOTE A: VIT− trip voltage is typically 5% lower than the output voltage (95%VO). VIT− to VIT+ is the hysteresis voltage.

 

 

 

TERMINAL FUNCTIONS

TERMINAL

I/O

DESCRIPTION

NAME

NO.

 

 

EN1

5

I

Active low enable for VOUT1

EN2

6

I

Active low enable for VOUT2

GND

8

Ground

MR

4

I

Manual reset input, active low, pulled up internally

NC

1, 11, 20

No connection

PG1

16

O

Open drain output, low when VOUT1 voltage is less than 95% of the nominal regulated voltage

PG2

15

O

Open drain output, low when VOUT2 voltage is less than 95% of the nominal regulated voltage

RESET

7

I

Open drain output, SVS (power-on reset) signal, active low

VIN1

2, 3

I

Input voltage of regulator 1

VIN2

9, 10

I

Input voltage of regulator 2

VOUT1

18, 19

O

Output voltage of regulator 1

VOUT2

12, 13

O

Output voltage of regulator 2

VSENSE2/FB2

14

I

Regulator 2 output voltage sense/regulator 2 feedback for adjustable

VSENSE1/FB1

17

I

Regulator 1 output voltage sense/regulator 1 feedback for adjustable

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Copyright © 2000–2007, Texas Instruments Incorporated

TPS70845, TPS70848 TPS70851, TPS70858

TPS70802

www.ti.com

SLVS301D–JUNE 2000–REVISED DECEMBER 2007

Detailed Description

The TPS708xx low dropout regulator family provides dual regulated output voltages with independent enable functions. These devices provide fast transient response and high accuracy with small output capacitors, while drawing low quiescent current. Other features are integrated SVS (power-on reset, RESET) and power good (PG1, PG2) that monitor output voltages and provide logic output to the system. These differentiated features provide a complete power solution.

The TPS708xx, unlike many other LDOs, features very low quiescent current that remains virtually constant even with varying loads. Conventional LDO regulators use a PNP pass element, the base current of which is directly proportional to the load current through the regulator (IB = IC/β). The TPS708xx uses a PMOS transistor to pass current; because the gate of the PMOS is voltage-driven, operating current is low and stable over the full load range.

Pin Functions

Enable (EN1, EN2)

The EN terminals are inputs that enable or shut down each respective regulator. If EN is at a voltage high signal, the respective regulator is in shutdown mode. When EN goes to voltage low, the respective regulator is enabled.

Power-Good (PG1, PG2)

The PG terminals are open drain, active high output terminals that indicate the status of each respective

regulator. When VOUT1 reaches 95% of its regulated voltage, PG1 goes to a high impedance state. When VOUT2 reaches 95% of its regulated voltage, PG2 goes to a high impedance state. Each PG goes to a low impedance

state when its respective output voltage is pulled below 95% (that is, goes to an overload condition) of its regulated voltage. The open drain outputs of the PG terminals require a pull-up resistor.

Manual Reset Pin

MR is an active low input terminal used to trigger a reset condition. When MR is pulled to logic low, a POR (RESET) occurs. The terminal has a 6-μA pull-up current to VIN1.

Sense (VSENSE1, VSENSE2)

The sense terminals of fixed-output options must be connected to the regulator outputs, and the connection should be as short as possible. Internally, the sense terminal connects to high-impedance, wide-bandwidth amplifiers through a resistor-divider network and noise pickup feeds through to the regulator output. It is essential to route the sense connection in such a way as to minimize or avoid noise pickup. Adding RC networks between sense terminals and VOUT terminals to filter noise is not recommended because these networks can cause the regulators to oscillate.

Copyright © 2000–2007, Texas Instruments Incorporated

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TPS70845, TPS70848

TPS70851, TPS70858

TPS70802

www.ti.com

SLVS301D–JUNE 2000–REVISED DECEMBER 2007

FB1 and FB2

FB1 and FB2 are input terminals used for adjustable-output devices and must be connected to the external feedback resistor divider. FB1 and FB2 connections should be as short as possible. It is essential to route them in such a way as to minimize or avoid noise pickup. Adding RC networks between FB terminals and VOUT terminals to filter noise is not recommended because these networks can cause the regulators to oscillate.

RESET Indicator

The TPS708xx features a RESET (SVS, POR, or power on reset). RESET can be used to drive power on reset circuitry or a low-battery indicator. RESET is an active low, open drain output that indicates the status of the manual reset pin (MR). When MR is in a high-impedance state, RESET goes to a high impedance state after a

120-ms delay. To monitor VOUT1, the PG1 output pin can be connected to MR. To monitor VOUT2, the PG2 output pin can be connected to MR. The open drain output of the RESET terminal requires a pull-up resistor. If RESET

is not used, it can be left floating.

VIN1 and VIN2

VIN1 and VIN2 are inputs to each regulator. Internal bias voltages are powered by VIN1.

VOUT1 and VOUT2

VOUT1 and VOUT2 are output terminals of each regulator.

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