Datasheet

4
LT1776
TYPICAL PERFORMANCE CHARACTERISTICS
UW
Minimum Input Voltage vs
Temperature
TEMPERATURE (°C)
–50
7.4
7.2
7.0
6.8
6.6
6.4
6.2
6.0
25 75
1776 G01
–25 0
50 100 125
INPUT VOLTAGE (V)
SWITCH CURRENT (mA)
0
SWITCH VOLTAGE (V)
1.50
1.25
1.00
0.75
0.50
0.25
0
300 500
1776 G02
100 200
400 600 700
125°C
–55°C
25°C
DUTY CYCLE (%)
0
SWITCH CURRENT LIMIT (mA)
1000
800
600
400
200
0
80
1776 G03
2010 30 50 70 90
40
60
100
T
A
= 25°C
Switch-On Voltage vs
Switch Current
Switch Current Limit vs
Duty Cycle
SHDN Pin Shutdown Threshold
vs Temperature
TEMPERATURE (°C)
–50
900
800
700
600
500
400
300
200
25 75
LT1776 G04
–25 0
50 100 125
SHDN PIN VOLTAGE (mV)
SHDN PIN VOLTAGE (V)
0
SHDN PIN INPUT CURRENT (µA)
5
0
–5
–10
–15
–20
4
1776 G05
1
2
3
5
25°C
–55°C
125°C
SHDN Pin Input Current
vs Voltage
TEMPERATURE (°C)
–50
1.30
1.28
1.26
1.24
1.22
1.20
25 75
LT1776 G06
–25 0
50 100 125
SHDN PIN VOLTAGE (V)
UPPER THRESHOLD
LOWER THRESHOLD
SHDN Pin Lockout Thresholds
vs Temperature
TEMPERATURE (°C)
SWITCHING FREQUENCY (kHz)
215
210
205
200
195
190
185
1776 G07
–50 25 75
–25 0
50 100 125
Switching Frequency
vs Temperature
Minimum Synchronization Voltage
vs Temperature
Switch Minimum On-Time
vs Temperature
TEMPERATURE (°C)
MINIMUM SYNCHRONIZATION VOLTAGE (V)
2.25
2.00
1.75
1.50
1.25
1.00
0.75
1776 G08
–50 25 75
–25 0
50 100 125
TEMPERATURE (°C)
SWITCH MINIMUM ON-TIME (ns)
600
500
400
300
200
100
0
1776 G09
–50 25 75
–25 0
50 100 125
V
IN
= 40V
R
L
= 39Ω
FB =