Datasheet

LT1912
3
1912fa
PARAMETER CONDITIONS MIN TYP MAX UNITS
Feedback Voltage
l
780
775
790
790
800
805
mV
mV
FB Pin Bias Current (Note 3) V
FB
= 0.8V, V
C
= 0.4V
l
7 30 nA
FB Voltage Line Regulation 4V < V
IN
< 36V 0.002 0.01 %/V
Error Amp g
m
25 µMho
Error Amp Gain 1000
V
C
Source Current 45 µA
V
C
Sink Current 45 µA
V
C
Pin to Switch Current Gain 3.5 A/V
V
C
Clamp Voltage 2 V
Switching Frequency R
T
= 187k 160 200 240 kHz
Minimum Switch Off-Time
l
60 150 nS
Switch Current Limit Duty Cycle = 5% 3.2 3.7 4.2 A
Switch V
CESAT
I
SW
= 2A 500 mV
Boost Schottky Reverse Leakage V
SW
= 10V, V
BD
= 0V 0.02 2 µA
Minimum Boost Voltage (Note 4)
l
1.5 2.1 V
BOOST Pin Current I
SW
= 1A 22 35 mA
RUN/SS Pin Current V
RUN/SS
= 2.5V 5 10 µA
RUN/SS Input Voltage High 2.5 V
RUN/SS Input Voltage Low 0.2 V
SYNC Low Threshold 0.5 V
SYNC High Threshold 0.7 V
SYNC Pin Bias Current V
SYNC
= 0V 0.1 µA
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: The LT1912E is guaranteed to meet performance specifications
from 0°C to 125°C. Specifications over the –40°C to 125°C operating
temperature range are assured by design, characterization and correlation
with statistical process controls.
Note 3: Bias current flows out of the FB pin.
Note 4: This is the minimum voltage across the boost capacitor needed to
guarantee full saturation of the switch.
ELECTRICAL CHARACTERISTICS
The l denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
IN
= 10V, V
RUN/SS
= 10V V
BOOST
= 15V, V
BD
= 3.3V unless otherwise
noted. (Note 2)