SC1592M

Rev 2.1

7

Description

The SC1592 is a 3A low dropout high performance linear

voltage regulator. The SC1592 can be used for voltage

applications as low as 0.8V and is ideal for down conversion

utilizing dual supply configuration. This allows for

extremely low dropout voltages with excellent load and

line regulation. The SC1592 can be utilized in high voltage

adequate thermal management.

SC1592 is designed to meet stringent requirements of

current generation microcontrollers and other sensitive

electronic devices. This is possible by employing an

needs to be at least 1.5V greater than the output voltage in

order to achieve low dropout, typically less than 300mV.

Unlike most of the other high current linear regulators, the

SC1592 provides a programmable current limit which can

be set with a single resistor. The value of the programming

resistor is:













×

≈

LIM

OUT

LIM

I

V

R

240

where ILIM = selected current limit value

VOUT = regulated output voltage

RLIM = programmable current limit resistor

The SC1592 has a fast transient response that allows it to

handle large load changes associated with high current

applications. Proper selection of the output capacitor and

its ESR value determines stable operation and optimizes

performance.

The typical application shown in Figure 2 was tested with a

wide range of different capacitors. The circuit was found to

be unconditionally stable with capacitor values from 47μF

to 330μF and ESR ranging from 0.5mΩ to greater than

75mΩ.

It’s recommended to maintain 5-10mA through the output

divider network in order to have a tight load and line

regulation. Initial accuracy of the internal voltage reference

VREF = 0.8V ±1% over full temperature range. This

commands the use of 0.5% or better accuracy resistors to

build a precision power supply.

CNTL

IN

EN

GND

ILIM

SENSE

OUT

SC1592M

C1

2.2μF

C2

22μF

R1

100

R2

66.5

R3

53

C3

100μF

10k

.

8

.

0

3

2

1

typ

V

V

V

R

R

V

REF

REF

OUT

=

•











 +

=

Figure 2

The circuit in Figure 2 shows a typical application of 2.5V to

1.8V conversion with a 3.3V control supply and the load

range of up to 3A steady state. Considering the approximate

2W power being dissipated by the pass element of the

SC1592, we are still able to choose an SO-8 EDP package

allocated for adequate heat transfer. The ambient

temperature in this case should not exceed 50°C.

Input capacitor: A minimum of 10μF ceramic capacitor is

recommended to be placed directly next to the Vin pin. This

allows for the device being some distance from any bulk

capacitance on the rail. Additionally, bulk capacitance may

be added close to the input supply pin of the SC1592 to

ensure that Vin does not sag, improving load transient

response.

Output capacitor: A minimum bulk capacitance of 33μF,

along with a 0.1μF ceramic decoupling capacitor is

recommended. Increasing the bulk capacitance will improve

the overall transient response. The use of multiple lower

value ceramic capacitors in parallel to achieve the desired

bulk capacitance will not cause stability issues. Although

designed for use with ceramic output capacitors, the SC1592

is extremely tolerant of output capacitor ESR values and

thus will also work comfortably with electrolytic output

capacitors.