Datasheet

3
LT1505
1505fc
PARAMETER CONDITIONS MIN TYP MAX UNITS
Preset Battery Voltage (12.3V, 16.4V, 12.6V, 16.8V)
All Preset Battery Voltages Measured at BAT2 Pin 0.5 %
Preset Battery Voltage Tolerance (V
BAT
+ 0.3V) ≤ V
CC
≤ 24V ● –1 1 %
BAT2 Pin Input Current V
BAT2
= V
PRESET
– 1V ● 6 µA
Voltage Setting Resistors Tolerance (R4, R5, R6, R7) –40 40 %
Shutdown
Undervoltage Lockout (TGATE and BGATE “Off”) Measured at UV Pin ● 6.3 6.7 7.25 V
Threshold (Note 9)
UV Pin Input Current 0V ≤ V
UV
≤ 8V ● –1 5 µA
Reverse Current from Battery in Micropower V
BAT
≤ 20V, V
UV
≤ 0.4V, 10 50 µA
Shutdown (Note 10) V
CC
= V
SW
= Battery Voltage
Shutdown Threshold at SHDN Pin When V
CC
● 12V
is Connected
SHDN Pin Current 0V ≤ V
SHDN
≤ 3V 8 µA
Supply Current in Shutdown V
CC
≤ 24V 15 20 mA
(V
SHDN
is Low, V
CC
is Connected)
Minimum I
PROG
for Switching “On” –1 –4 –22 µA
Minimum I
PROG
for Switching “Off” at V
PROG
≤ 1V ● –1 –2.4 mA
Current Sense Amplifier CA1 Inputs (SENSE, BAT)
Input Bias Current (SENSE, BAT) V
SHDN
= High ● –50 –120 µA
V
SHDN
= Low (Shutdown) –10 µA
Input Common Mode Low ● –0.25 V
Input Common Mode High ● V
CC
– 0.3 V
SPIN Input Current V
SHDN
= High, V
SPIN
≥ 2V (Note 8) ● 2mA
V
SHDN
= Low (Shutdown) 10 µA
Oscillator
Switching Frequency (f
NOM
) 180 200 220 kHz
Switching Frequency Tolerance ● 170 200 230 kHz
SYNC Pin Input Current V
SYNC
= 0V –0.5 mA
V
SYNC
= 2V –30 µA
Synchronization Pulse Threshold on SYNC Pin 0.9 1.2 2.0 V
Synchronization Frequency ● 240 280 kHz
Maximum Duty Cycle
V
BOOST
Threshold to Turn TGATE Off Measured at (V
BOOST
– V
SW
)
(Comparator A2) (Note 4) Low to High
● 6.8 7.3 7.6 V
Hysteresis 0.25 V
Maximum Duty Cycle of Natural Frequency 200kHz ● 85 90 %
(Note 5)
Current Amplifier CA2
Transconductance V
C
= 1V, I
VC
= ±1µA 150 200 300 µmho
Maximum V
C
for Switch Off ● 0.6 V
I
VC
Current (Out of Pin) V
C
≥ 0.6V ● 50 µA
V
C
< 0.45V ● 3mA
V
C
at Shutdown V
SHDN
= Low (Shutdown) ● 0.35 V
ELECTRICAL CHARACTERISTICS
The ● denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. V
CC
= 18V, V
BAT
= 12.6V, V
CLN
= V
CC
(LT1505), no load on any
outputs unless otherwise noted.