LT1528 Linear Technology, LT1528 Datasheet - Page 6

• Manufacturer Part Number: LT1528
• Description: 3A Low Dropout Regulator for Microprocessor Applications
• Manufacturer: Linear Technology

TYPICAL PERFORMANCE CHARACTERISTICS
LT1528
PIN
6
OUTPUT (Pin 1): The Output pin supplies power to the
load. A minimum output capacitor of 3.3 F is required to
prevent oscillations. Larger values will be needed to achieve
the transient performance required by high speed micro-
processors. See the Applications Information section for
more on output capacitance and reverse output character-
istics.
SENSE (Pin 2): The Sense pin is the input to the error
amplifier. Optimum regulation will be obtained at the point
where the Sense pin is connected to the Output pin. For
most applications the Sense pin is connected directly to
the Output pin at the regulator. In critical applications small
voltage drops caused by the resistance (R
U
FUNCTIONS
–100
–50
100
U
80
70
60
50
40
30
20
10
50
0
0
3
2
1
0
10
Ripple Rejection
Transient Response
0
I
V
OUT
IN
20
= 6V + 50mV
= 1.5A
100
40
U
SOLID TANTALUM
60
SOLID TANTALUM
C
FREQUENCY (Hz)
OUT
80
1k
RMS
TIME ( s)
= 4 47 F
C
W
100
OUT
RIPPLE
= 47 F
120
10k
U
140
V
C
C
IN
IN
OUT
= 5V
= 3.3 F
100k
160
= 47 F
LT1528 • TPC19
LT1528 • TPC21
180
P
200
1M
) of PC traces
between the regulator and the load, which would normally
degrade regulation, may be eliminated by connecting the
Sense pin to the Output pin at the load as shown in Figure
1 (Kelvin Sense Connection). Note that the voltage drop
across the external PC traces will add to the dropout
voltage of the regulator. The Sense pin bias current is
150 A at the nominal regulated output voltage. See Sense
Pin Current vs Temperature in the Typical Performance
Characteristics section. This pin is internally clamped to
– 0.6V (one V
The Sense pin can also be used with a resistor divider to
achieve output voltages above 3.3V. See the Applications
Information section for information on adjustable operation.
–100
–50
–10
–15
–20
–25
–30
100
50
–5
0
3
2
1
0
0
–50
Load Regulation
Transient Response
0
BE
V
C
C
20
).
IN
IN
OUT
–25
= 5V
= 3.3 F
= 4 47 F
40
60
0
TEMPERATURE ( C)
V
80
IN
TIME ( s)
25
= V
100
OUT
I
50
LOAD
120
(NOMINAL) + 1V
= 1mA TO 3A
140
75
160
LT1528 • TPC22
LT1528 • TPC20
100
180
200
125