Datasheet

Background
1-2
1.1 Background
The purpose of the UC385EVM-207 is to facilitate evaluation of the UCx82-x
and UCx85-x families of devices. The UC385EVM consists of the SLVP207
PCB, one UC385-ADJ adjustable, 5-A linear regulator in a TO-263 package,
and supporting passive components. The adjustable device has been
configured to output 1.2 V using a feedback resistor. The SLVP207 PCB is
designed to accommodate multiple devices with similar pin-outs in different
packages (i.e., TO–220, TO–263, or SOT–223). Specifically, in addition to the
UCx82 and UCx85 families, the SLVP207 can be used with the TPS755xx,
TPS756xx, TPS757xx, TPS758xx, TPS759xx, TPS725xx, TPS725xx,
TPS795xx, TPS796xx, and TPS786xx families as well as any other device in
the same package and with the same pinout. Therefore, some component
footprints on the PCB are not populated.
The UCx82-x and UCx85-x families of high current LDO linear regulators use
a NPN pass element and have very fast transient response, low noise, and
high PSRR. In addition, these regulators have separate input and bias voltage
pins and low dropout. The bias voltage input powers the internal circuitry of the
IC. The input voltage pin needs to be at least 500 mV above the output voltage
and provides current only for the NPN pass element; therefore, regulator
efficiency can be improved and power dissipation can be reduced compared
to typical regulators requiring input voltages of 2.5 V or more. Additional
features, as well as detailed specifications, of the UCx82-x and UCx85-x
regulator families can be found in the UCx82-x data sheet (SLUS317) or the
UCx85-x data sheet (SLUS212).
1.2 Performance Specification Summary
Table 1–1 provides a summary of the performance specifications. All tests
performed using V
B
= 5.0 V, V
I
= 1.8 V, and C
O
= 100 µF unless otherwise
specified.
Table 1–1.Performance Specification Summary
Specification Test Conditions Min Typ Max Units
Input voltage Min(V
IN–
V
OUT
) = 500 mV 1.7 1.8 7.5 V
Bias voltage Min(V
B
–V
OUT
) = 2.2 V 3.4 5.0 7.5 V
Output voltage 1.2 V
Output current range 0.01 5 A
Load regulation
†
0.5 4 mV
I 10 mA to 5 A t 10 s
–50 mV
PK
Load transient response
I
O
= 10 mA to 5 A, t
(rise)
= 10 µs
32 µs
Load transient response
I 10 mA to 5 A t 5 s
75 mV
PK
I
O
= 10 mA to 5 A, t
(fall)
= 5 µs
40 µs
PSRR f = 1kHz, I
O
= 5 A 80 dB
Noise
V
I
= 3.5 V, I
OUT
= 2.5 A,
BW = 200 Hz to 100 kHz, C
OUT
= 100 µF
35 µV
RMS
†
Per data sheet