lt1528ct-pbf Linear Technology Corporation, lt1528ct-pbf Datasheet - Page 6

• Manufacturer Part Number: lt1528ct-pbf
• Description: 3a Low Dropout Regulator For Microprocessor Applications
• Manufacturer: Linear Technology Corporation

LT1528
TYPICAL PERFOR A CE CHARACTERISTICS
PI FU CTIO S
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
microprocessors. See the Applications Information sec-
tion for more on output capacitance and reverse output
characteristics.
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
6
U
–100
U
–50
100
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
RMS
1k
TIME ( s)
= 4 47 F
C
W
OUT
100
RIPPLE
= 47 F
120
10k
U
140
V
C
C
IN
IN
OUT
100k
160
= 5V
= 3.3 F
LT1528 • TPC19
LT1528 • TPC21
= 47 F
180
200
1M
P
) of PC
traces between the regulator and the load, which would
normally degrade regulation, may be eliminated by con-
necting 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
–10
–20
–25
–30
–50
–15
100
–5
50
0
0
3
2
1
0
–50
Load Regulation
Transient Response
0
V
C
C
IN
IN
OUT
20
–25
= 5V
= 3.3 F
= 4 47 F
40
0
60
TEMPERATURE ( C)
V
80
IN
25
TIME ( s)
BE
= V
100
).
OUT
I
50
LOAD
120
(NOMINAL) + 1V
= 1mA TO 3A
140
75
160
LT1528 • TPC22
LT1528 • TPC20
100
180
125
200
1528fa