Typical Performance Characteristics: continued

6

0.0

83.0

Temperature (C)

40.0

60.0

80.0

100.0

81.0

79.0

77.0

75.0

73.0

71.0

69.0

67.0

65.0

20.0

120.0

160.0

140.0

Adjust Pin Current vs Temperature

Application Notes

50

0

-50

-100

7

0

02

5

0

Time (

ms)

100

13

4

mF

mF

mF

mF

Current Step Transient Response

The CS52510-1 linear regulator provides adjustable voltages

from 1.25V to 5V at currents up to 10A. The regulator is pro-

tected against short circuits, and includes a thermal shut-

down circuit with hysteresis. The output, which is current

limited, consists of a PNP-NPN transistor pair and requires

an output capacitor for stability. A detailed procedure for

selecting this capacitor is included in the Stability

Considerations section.

The CS52510-1 utilizes a two supply approach to maximize

efficiency. The collector of the power device is brought out to

control circuitry and the drive for the output NPN transistor.

age. Special care has been taken to ensure that there are no

supply sequencing problems. The output voltage will not

turn on until both supplies are operating. If the control volt-

age comes up first, the output current will be typically limit-

ed to about 3mA until the power input voltage comes up. If

the power input voltage comes up first the output will not

turn on at all until the control voltage comes up. The output

can never come up unregulated.

The CS52510-1 can also be used as a single supply device

with the control and power inputs tied together. In this

mode, the dropout will be determined by the minimum con-

trol voltage.

Output Voltage Sensing

The CS52510-1 five terminal linear regulator includes a dedi-

cated Vsense function. This allows for true Kelvin sensing of

the output voltage. This feature can virtually eliminate errors

in the output voltage due to load regulation. Regulation will

be optimized at the point where the sense pin is tied to the

output.

Adjustable Operation

This LDO adjustable regulator has an output voltage range

of 1.25V to 5V. An external resistor divider sets the output

voltage as shown in Figure 1. The regulatorÕs voltage sensing

error amplifier maintains a fixed 1.253V reference between

the output pin and the adjust pin.

that adds to the 1.253V across R1 and sets the overall output

voltage. The adjust pin current (typically 50µA) also flows

put voltage is set according to the formula:

pin current.

tracking over temperature. The divider resistors should be

placed as close to the load as possible.

reference voltage drops across R1.

V

SENSE

V

OUT

V

CONTROL

V

POWER

CS52510-1

R1

Adjust

R2

Design Guidelines

Theory of Operation