Datasheet

UCC2845, UCC28412, UCC284ADJ, UCC3845, UCC38412, UCC384ADJ
LOW-DROPOUT 0.5-A NEGATIVE LINEAR REGULATOR
SLUS234D JANUARY 2000 REVISED FEBRUARY 2002
3
POST OFFICE BOX 655303 DALLAS, TEXAS 75265
electrical characteristics T
A
= 0°C to 70°C for the UCC384 and 40°C to 85°C for the UCC284,
VIN = VOUT 1.5 V, I
OUT
= 0 mA, C
OUT
= 4.7 µF, and CT = 0.015 µF. For UCC384ADJ, VOUT is set
to 3.3V (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
UCC3845 Fixed 5-V 0.5-A Regulation Section
Out
p
ut voltage
T
A
= 25°C
5.075 5 4.925 V
Output voltage
Over all conditions 5.100 4.850 V
Line regulation VIN = 5.2 V to 15 V 1.5 10 mV
Load regulation I
OUT
= 0 mA to 0.5 A 0.1 0.25 %
Output noise voltage
T
A
= 25°C, BW = 10 Hz to 10 kHz
200
µVRMS
Dro
p
out voltage VOUT VIN
I
OUT
0.5 A, VOUT = 4.8 V 0.20 0.50 V
Dropout voltage, VOUT VIN
I
OUT
50 mA, VOUT = 4.8 V 20 50 mV
UCC3845 Fixed 5-V 0.5-A Power Supply Section
Input voltage range 15 5.2 V
Quiescent current charge pump on VIN = 4.85 V, See Note 1 280 350
µA
Quiescent current VIN = 15 V 200 250
µA
Quiescent current in shutdown
VIN = 13 V, SD/CT = 0 V
T
A
= 0°C to 85°C, See Note 2
15 45
µA
Quiescent current in shutdown
VIN = 13 V, SD/CT = 0 V
T
A
= 40°C to 0°C, See Note 2
100
µA
Shutdown threshold At shutdown pin (SD/CT) 1.0 0.7 0.4 V
Shutdown input current SD/CT = 0 V 5 10 25
µA
Output leakage in shutdown
VIN = 15 V, VOUT = 0 V,
See Note 3
1 50
µA
Overtemperature shutdown 140
°C
Overtemperature hysteresis 20
°C
UCC3845 Fixed 5-V 0.5-A Current Limit Section
Peak current limit VOUT = 0 V 0.7 1.1 1.5 A
Overcurrent threshold 0.55 0.7 0.9 A
Current limit duty cycle VOUT = 0 V 2.5 4 %
Overcurrent time out, t
ON
VOUT = 0 V 300 500 700
µs
UCC38412 Fixed 12-V 0.5-A Regulation Section
Out
p
ut voltage
T
A
= 25°C
12.18 12 11.82 V
Output voltage
Over all conditions 12.24 11.64 V
Line regulation VIN = 12.5 V to 15 V 5 15 mV
Load regulation I
OUT
= 0 mA to 0.5 A 0.1 0.3 %
Output noise voltage
T
A
= 25°C BW = 10 Hz to 10 kHz
200
µVRMS
Dro
p
out voltage VOUT VIN
I
OUT
0.5 A, VOUT = 11.6 V 0.15 0.5 V
Dropout voltage, VOUT VIN
I
OUT
50 mA, VOUT = 11.6 V 15 50 mV
UCC38412 Fixed 12 V-0.5-A Power Supply Section
Input voltage range 15 12.5 V
Quiescent current VIN = 15 V 220 350
µA
Quiescent current in shutdown
VIN = 13 V, SD/CT = 0 V
T
A
= 0°C to 85°C, See Note 2
15 45
µA
Quiescent current in shutdown
VIN = 13 V, SD/CT = 0 V
T
A
= 40°C to 0°C, See Note 2
100
µA
NOTES: 1. The internal charge pump is enabled only for dropout condition with low VIN. Only in this condition is the charge pump required to
provide additional output FET fate drive to maintain dropout specifications. For conditions where the charge pump is not required,
it is disabled, which lowers overall device power consumption.
2. Ensured by design. Not production tested.
3. In the application during shutdown mode, output leakage current adds to quiescent current.