TS2950-51 series

1-6

2003/12 rev. B

TS2950/TS2951 series

150mA Ultra Low Dropout Positive Voltage Regulator

Input Voltage Range up to 30V

Output Current up to 150mA

Low Drop Out Voltage 0.4V

General Description

The TS2950/A & TS951/A are low power voltage regulators. These devices are excellent choice for use in
battery-powered applications such as cordless telephone, radio control systems, and portable computers.
The TS2950/A & TS2951/A is features very low quiescent current (75uA Typ.) and very low drop output voltage (Typ.
40uV at light load and 380 mV at 100 mA). This includes a tight initial tolerance of 0.5% typ.(A version), extremely good
load and line regulation 0.05% typ. and very low output temperature coefficient, making the TS2950/A & TS2951/A useful
as a low-power voltage reference.
TS2951/A have other key additional feature of unregulated input voltage transient of -20V below ground (reverse battery).
The error flag output feature is used as power-on reset for warn of a low output voltage, due to following batteries on
input. The logic-compatible shutdown input which enable the regulator to be switched on/off. The regulator output voltage
may be pin-strapped for a 5.0, 3.3 & 3V of programmed from 1.24V to 29V with external pair of resistors. Using of as
design, processing and testing techniques make TS2950/A & TS951/A superior over similar products.
The TS2950/A is offered in 3-pin TO-92 package, The TS2951/A is available in 8-pin plastic SOP-8 package.

Application

Battery powered systems

Portable

instrumentation

Avionics

Automotive

Electronics

SMPS

Post-Regulator

Voltage

Reference

Portable/Palm top / Notebook computers

Portable

consumer

equipment

Radio control system

Features

Output voltage available in 5V, 3.3V & 3V

Extremely low quiescent current

Low

dropout

voltage

Extremely tight load and line regulation

Very low temperature coefficient

Need only 1uF for stability

Unregulated DC input can withstand -20V reverse

battery and +60V positive transients

Use as Regulator or Reference

Stable with low-ESR output capacitors

Current and thermal limiting

Direct replacement for LP2950 & LP2951 sockets

TS2951 VERSIONS ONLY

Error Flag warns of output dropout

Logic-Controlled

electronic

shutdown

Additional voltage tap

Output voltage sense

Output programmable from 1.24 to 29V

Ordering Information

Note: Where xx denotes voltage option, available are

5.0V, 3.3V and 3V. Contact factory for additional
voltage options.

Part No.

Operating Temp. Package

TS2950CT-

TO-92

TS2951CS-

-40 ~ +85

SOP-8

TS2950ACT-

TO-92

TS2951ACS-

-20 ~ +85

SOP-8

Pin assignment

TO-92

1. Output

2. Ground

3. Input

Pin assignment

SOP-8

1. Output
2. Sense
3. Shutdown
4. Ground
5. Error
6. Voltage tap
7. Feedback
8. Input

TS2950-51 series

2-6

2003/12 rev. B

Absolute Maximum Rating

Input Supply Voltage

Vin

- 0.3 ~ +30

Feedback Input Voltage

Vfeedback

- 1.5 ~ +30

Shutdown Input Voltage

Vshutdown

- 0.3 ~ +30

Error Comparator Output Voltage

Verror

- 0.3 ~ +30

Power Dissipation

Internally Limited

TS2950/2951

- 40 ~ +125

Operating Junction Temperature

Range

TS2950A/2951A

- 20 ~ +125

Storage Temperature Range

STG

-65 ~ +150

Lead Temperature (Soldering 5 second)

STG

260

TS2950/A & TS2951/A Electrical Characteristics

(Vin=15V, Ta=25

C unless otherwise specified.)

Parameter Test

Conditions

(note 2)

Min

Typ

Max

Unit

TS2950/TS2951 |0.990|

|1.010|

Tj= 25

TS2950A/TS2951A |0.995|

|1.005|

TS2950/TS2951 |0.980|

|1.020|

Full Operating temp

TS2950A/TS2951A |0.988|

|1.012|

TS2950/TS2951 |0.975|

|1.025|

Output Voltage

100uA

100mA

Tj(max)

TS2950A/TS2951A |0.985|

5.0

3.3

3.0

|1.015|

TS2950/TS2951 --

150

Output Voltage Temperature

Coefficient

(Note 1)

TS2950A/TS2951A -- 20 100

ppm/

Line Regulation (Note 3)

Vin 30V (Note 4)

0.04

0.2

Load Regulation (Note 3)

100uA

100mA --

0.1

0.3

Dropout Voltage (Note 5)

=100uA

=100mA

-- 50

380

450

Ground Current

=100uA

=100mA

-- 75

120

Dropout Ground Current

Vin= 4.5V, I

= 100uA

110

170

Current Limit

Vout= 0

160

200

Thermal Regulation

0.05

0.2

Output Noise, 10Hz

to 100KHz

Bypass=0.01uF

(pins 7 to 1 TS2951/A)

= 1uF

= 200uF

= 3.3uF

-- 430

160

100

-- uV/

rms

8-Pin TS2951/A Versions only

TS2951 1.21 1.27

Reference Voltage

TS2951A 1.22 1.26

TS2951 1.185

1.285

Reference Voltage

(Note6)

TS2951A 1.19

1.235

1.27

TS2950-51 series

3-6

2003/12 rev. B

TS2951/A Electrical Characteristics

(continues)

(Vin= 15V, Ta= 25

C unless otherwise specified.)

Parameter Test

Conditions

(note 2)

Min

Typ

Max

Unit

Feedback Pin Bias Current

Reference Voltage Temperature

Coefficient

(Note 7)

-- 20 --

ppm/

Feedback Pin Bias Current

Temperature Coefficient

-- 0.1 --

nA/

Error Comparator

Output Leakage Current

= 30V

0.01

Output Low Voltage

Vin= 4.5V, I

= 400uA

150

250

Upper Threshold Voltage

(Note 8)

Power Threshold Voltage

(Note 8)

Hysteresis

(Note

-- 15 -- mV

Shutdown Input

Output Logic Voltage

Low (Regulator ON)

High(Regulator OFF)

2.0

1.3

0.7

Shut down Pin Current

Vs = 2.4V

Vs = 30V

-- 30

450

600

Regulator Output Current in

Shutdown

(Note 9)

Note 1: Output voltage temperature coefficients defined as the worst case voltage change divided by the total

temperature range.

Note 2: Unless otherwise specified all limits guaranteed for T

= 25

C, Vin= 6V, I

= 100uA and C

= 100uF. Additional

conditions for the 8-pin versions are feedback tied to 5V, 3.3V & 3V tap output Sense (Vout = 5V, 3.3V & 3V) and
Vshutdown

0.8V.

Note 3: Regulation is measured at constant junction temperature, using pulse testing with a low duty cycle. Changes in

output voltage due to heating effects are covered under the specification for thermal regulation.

Note 4: Line regulation for the TS2951 is tested at 85

C for I

= 1mA.For I

= 100uA and Tj= 125

C, line regulation is

guaranteed by design to 0.2%.

Note 5: Dropout Voltage is defined as the input to output differential at which the output voltage drops 100mV below its

nominal value measured at 1V differential at very low value of programmed output voltage, the minimum input
supply voltage of 2V (2.3V over temperature) must be taken in to account.

Note 6: Vref

Vout (Vin-1V), 2.3 Vin 30V, 100uA I

100mA, Tj Tj(max)

Note 7: reference voltage temperature coefficient is defined as the worst case voltage change divided by the total

temperature range.

Note 8: Comparator thresholds are expressed in terms of a voltage differential at the feedback terminal below the

nominal reference voltage measured at 6V input. To express these thresholds in terms of output voltage change,
multiply by the error amplifier gain= Vout / Vref = (R1+R2) / R2. For example, at a programmed output voltage of
5V, the Error output is guaranteed to go low when the output drops by 95 mV X 5V / 1.250 = 384mV. Thresholds
remain constant as a percent of Vout as Vout is varied with the dropout warning occurring at typically 5% below
nominal, 7.5% guaranteed.

TS2950-51 series

4-6

2003/12 rev. B

Application Hints

External Capacitors

For the stability of the TS2950/A & TS2951/A is requires
a 1.0uF(0.22uF is recommended for 3.0V & 3.3V) or
greater capacitor between output and ground. Oscillation
could occur without this capacitor. The tantalum or
aluminum electrolytic works fine; could use the film type
work but are not cost efficient. For the operation of below
-25

C solid tantalum is recommended since the many

aluminum type have electrolytes the freeze at about -30

C. The ESR of about 5 or less and resonant frequency

above 500KHz are most important parameter in the value
of Capacitor. The Capacitors value can be increased
without any limit. At lower values of output current, less
output capacitance is required for stability. For the
currents below 10mA the value of capacitor can be
reduce to 0.33uF and 0.1uF for 1mA. More output
capacitance needed for the 8-pin version at voltage
below 5V since it runs the error amplifier at lower gain. At
worst case 3.3uF or greater must be used for condition of
100mA load at 1.250V output.
The TS2950/A & TS2951/A is not like other low dropout
regulators will remain stable and regulation with no load
in addition to the internal voltage divider. This feature
very important in application, it is like CMOS RAM
keep-alive. The TS2951/A output voltage is set with
minimum load of 1uA and external resistors.
If at the input of TS2950/A & TS2951/A connected to
battery or between AC filter capacitor and input is 10
inches wire then 1uF tantalum or aluminum electrolytic
capacitor should be connected between input and
ground. Instability can occur if stray capacitor to feedback
terminal pin 7 of the TS2951/A. This could cause more
problems when using higher value of external to set the
output voltage. To fix this problem the 100pF capacitor
between output and feedback and increasing output
capacitance to 3.3uF.

Reducing Output Noise

It could be an advantage to reduce the AC noise present
at the output. One method is to reduce the regulator
bandwidth by increasing the value of the output
capacitor. This is the only method that noise could
reduce on the TS2950/A & TS2951/A, but is relatively
inefficient, as increasing capacitor from 1uF to 220uF
only decreases the noise from 430uV to 160uVrms for a
100KHz bandwidth at 5V output. Noise could be also
reduced by fourfold by a bypass capacitor across R1
since it reduces the high frequency gain from 4 to unity.

Pick Cbypass= 1 / 2R1

* 200Hz or choose 0.01uF

when doing this, the output capacitor must be increased
to 3.3uF to maintain stability. These change the output
noise from 430uV/rms for a 100 kHz bandwidth 5V,
3.3V & 3V output. With the bypass capacitor added,
noise no longer scales with output voltage so that
improvements are more dramatic higher output voltage.

Error Detection Comparator Output

The Compactor produces a logic low output whenever
the TS2951/A output falls of regulation by more than
around 5%. This is around 60 mV offset divided by the
1.235 reference voltage. Thus trip remains 5% below
nominal regardless of the programmed output voltage
of the regulator. The Figure 1 shows the timing diagram
depicting the ERROR signal and the regulator output
voltage as the TS2951/A input is ramped up and down.
The ERROR signal becomes low at around 1.3V input,it
goes high around 5V input (input voltage at which
Vout=4.75V). The TS2951/A dropout voltage depending
on the load, the input voltage trip point around 5V will
vary with load current. The output voltage trip point is
around 4.75V, it does not change with load. The error
comparator has an open-collector output which requires
an external pull-up resistor. Depending on the system
requirement, the resistor maybe returned to 5 or 3.3V
output or other supply voltage depending to the system
requirements. For determining the size of the resistor,
note that the output is sinking 400uA, this value adds to
battery drain in a low better condition, recommended
values 100K to 1M. If the output is unused this
resistor is not required.

Figure 1. Error Output Timing

TS2950-51 series

5-6

2003/12 rev. B

Application Hints (continued)

Programming The output Voltage

The TS2951/A output voltage is programmable for any
value from it reference voltage of 1.235V and it maximum
rating of 30V. For example for 5 volt needs to
pin-strapped and using the internal voltage divider by
tying pin 1 to 2 and pin 7 to pin 6. Refer to Figure 2, there
are two external resistor required for this programming.
Refer to the below equation for the programming the
output voltage:

Volt=Vref x (1+R1\R2)+I

* R1

The Vref is 1.235V and I

is the feedback bias current,

nominally -20nA. The minimum recommended load
current of 1uA forces an upper limit of 1.2Mon value of
R2, If no load presented the I

produces error of typically

2% in Vout which maybe eliminated at room temperature
by trimming R1. To improve the accuracy chooses the
value of R2=100K and this reduces the error by 0.17%
and increases the resistor program current by 12uA. The
TS2951/A typically draw 60uA at no load with pin 2
open-circuit, and this value does not look much.

Figure 2. Adjust Voltage

Block Diagram and Typical Applications Circuit

Электронный компонент: TS2951ACS-5.0