Datasheet

2
LT1680
LT1680CN
LT1680CSW
LT1680IN
LT1680ISW
ORDER PART
NUMBER
1
2
3
4
5
6
7
8
TOP VIEW
SW PACKAGE
16-LEAD PLASTIC SO WIDE
N PACKAGE
16-LEAD PDIP
16
15
14
13
12
11
10
9
SL/ADJ
C
T
I
AVG
SS
V
C
SGND
V
FB
V
REF
5V
REF
SYNC
12V
IN
GATE
PGND
RUN/SHDN
SENSE
–
SENSE
+
T
JMAX
= 125°C, θ
JA
= 75°C/ W (N)
T
JMAX
= 125°C, θ
JA
= 90°C/ W (SW)
(Note 1)
Power Supply Voltage (12V
IN
).................. –0.3V to 20V
Sense Amplifier Input Common Mode ...... –0.3V to 60V
GATE Pin Voltage....................... –0.3V to 12V
IN
+ 0.3V
RUN/SHDN Pin Voltage ......................... –0.3V to 12V
IN
All Other Pin Voltages ................................. –0.3V to 7V
5V Reference Output Current............................... 65mA
Operating Ambient Temperature Range
LT1680C.................................................. 0°C to 70°C
LT1680I .............................................. –40°C to 85°C
Storage Temperature Range ................ –65°C to 150°C
Lead Temperature (Soldering, 10 sec)................. 300°C
Consult factory for parts specified with wider operating temperature ranges.
ABSOLUTE AXI U RATI GS
WWWU
PACKAGE/ORDER I FOR ATIO
UU
W
ELECTRICAL CHARACTERISTICS
The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at T
A
= 25°C.
12V
IN
= 12V, V
VC
= 2V, V
FB
= V
REF
= 1.25V, C
GATE
= 3000pF, unless otherwise noted.
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
Supply and Protection
I
12VIN
DC Active Supply Current (Note 2) Gate Output On ● 15 22 mA
Gate Output Off 12 mA
DC Standby Supply Current V
RUN
< 0.5V ● 150 250 µA
V
RUN/SHDN
Shutdown Rising Threshold ● 1.15 1.25 1.35 V
V
SSHYST
Shutdown Threshold Hysteresis 25 mV
I
SS
Soft Start Charge Current ● 5814 µA
V
UVLO
Undervoltage Lockout Threshold - Falling ● 8.20 9.00 9.75 V
Undervoltage Lockout Threshold - Rising
● 9.35 9.95 V
Undervoltage Lockout Hysteresis ● 200 350 mV
5V Reference
V
REF5
5V Reference Voltage Line, Load and Temperature ● 4.75 5 5.25 V
5V Reference Line Regulation 10V ≤ 12V
IN
≤ 15V ● 3 5 mV/V
I
REF5
5V Reference Load Range - DC ● 10 mA
Pulse
● 20 mA
5V Reference Load Regulation 0 ≤ I
REF5
≤ 20mA ● –1.25 –2 V/A
I
SC
5V Reference Short-Circuit Current 45 mA
Error Amplifier
V
FB
Error Amplifier Reference Voltage Measured at Feedback Pin 1.242 1.250 1.258 V
● 1.235 1.265 V
I
FB
Feedback Input Current V
FB
= V
REF
● 0.1 0.5 1.0 µA
g
m
Error Amplifier Transconductance ● 1200 2000 3200 µmho
A
V
Error Amplifier Voltage Gain ● 1500 3000 V/V
I
VC
Error Amplifier Source Current ● 200 275 µA
Error Amplifier Sink Current V
FB
– V
REF
= 500mV ● 280 400 µA
V
VC
Absolute V
C
Clamp Voltage Measured at V
C
Pin 3.5 V