LTC1538-AUX Linear Technology, LTC1538-AUX Datasheet - Page 6

• Manufacturer Part Number: LTC1538-AUX
• Description: Dual High Efficiency/ Low Noise/ Synchronous Step-Down Switching Regulators
• Manufacturer: Linear Technology

200mV/DIV
LTC1538-AUX/LTC1539
20mV/DIV
6
TYPICAL PERFORMANCE CHARACTERISTICS
154
152
150
148
146
–10
10
–5
V
V
f
5
O
OUT
OUT
– 40
– 40
Normalized Oscillator Frequency
vs Temperature
Maximum Current Comparator
Threshold Voltage vs Temp
I
LOAD
Burst Mode Operation
–15
–15
= 50mA
10
10
TEMPERATURE ( C)
TEMPERATURE ( C)
35
35
60
60
85
85
W
110
110
1538/39 • G13
1538/39 • G10
1538/39 • G16
U
135
135
INDUCTOR
50mV/DIV
CURRENT
RUN/SS
5V/DIV
1A/DIV
V
OUT
3
1
0
4
2
– 40
Transient Response
I
Soft Start: Load Current vs Time
RUN/SS Pin Current vs
Temperature
LOAD
–15
= 50mA to 1A
10
TEMPERATURE ( C)
35
60
85
110
1538/39 • G11
1538/39 • G14
1538/39 • G17
135
50mV/DIV
– 0.25
– 0.75
–1.00
–1.50
–1.50
–1.25
11.8
12.2
12.1
12.0
11.9
11.7
V
OUT
0
– 40
Transient Response
Auxiliary Regulator Load
Regulation
0
SFB1 Pin Current vs
Temperature
I
LOAD
EXTERNAL PNP: 2N2907A
–15
= 1A to 3A
AUXILIARY LOAD CURRENT (mA)
40
10
TEMPERATURE ( C)
80
35
60
120
85
160
110
1538/39 • G12
1538/39 • G18
1538/39 • G15
135
200