Datasheet

3
LT1182/LT1183/LT1184/LT1184F
SYMBOL PARAMETER CONDITIONS MIN TYP MAX UNITS
I
Q
Supply Current LT1182/LT1183: 3V ≤ V
IN
≤ 30V ● 914 mA
LT1184/LT1184F: 3V ≤ V
IN
≤ 30V ● 6 9.5 mA
I
SHDN
SHUTDOWN Supply Current SHUTDOWN = 0V, CCFL V
C
= LCD V
C
= Open (Note 2) 35 70 µA
SHUTDOWN Input Bias Current SHUTDOWN = 0V, CCFL V
C
= LCD V
C
= Open 3 6 µA
SHUTDOWN Threshold Voltage ● 0.6 0.85 1.2 V
f Switching Frequency Measured at CCFL V
SW
and LCD V
SW
, I
SW
= 50mA, 175 200 225 kHz
I
CCFL
= 100µA, CCFL V
C
= Open, (LT1182) FBN = FBP =
1V, (LT1183) FB = 1V, (LT1182/LT1183) LCD V
C
= Open ● 160 200 240 kHz
DC(MAX) Maximum Switch Duty Cycle Measured at CCFL V
SW
and LCD V
SW
80 85 %
● 75 85 %
BV Switch Breakdown Voltage Measured at CCFL V
SW
and LCD V
SW
60 70 V
Switch Leakage Current V
SW
= 12V, Measured at CCFL V
SW
and LCD V
SW
20 µA
V
SW
= 30V, Measured at CCFL V
SW
and LCD V
SW
40 µA
I
CCFL
Summing Voltage 3V ≤ V
IN
≤ 30V, Measured on LT1182/LT1183 0.41 0.45 0.49 V
● 0.37 0.45 0.54 V
3V ≤ V
IN
≤ 30V, Measured on LT1184/LT1184F 0.425 0.465 0.505 V
● 0.385 0.465 0.555 V
∆I
CCFL
Summing Voltage for I
CCFL
= 0µA to 100µA 5 15 mV
∆Input Programming Current
CCFL V
C
Offset Sink Current CCFL V
C
= 1.5V, Positive Current Measured into Pin –5 5 15 µA
∆CCFL V
C
Source Current for I
CCFL
= 25µA, 50µA, 75µA, 100µA, ● 4.70 4.95 5.20 µA/µA
∆I
CCFL
Programming Current CCFL V
C
= 1.5V
CCFL V
C
to DIO Current Servo Ratio DIO = 5mA out of Pin, Measure I
VC
at CCFL V
C
= 1.5V ● 94 99 104 µA/mA
CCFL V
C
Low Clamp Voltage V
BAT
– V
BULB
= Bulb Protect Servo Voltage ● 0.1 0.3 V
CCFL V
C
High Clamp Voltage I
CCFL
= 100µA ● 1.7 2.1 2.4 V
CCFL V
C
Switching Threshold CCFL V
SW
DC = 0% ● 0.6 0.95 1.3 V
CCFL High-Side Sense Servo Current I
CCFL
= 100µA, I
VC
= 0µA at CCFL V
C
= 1.5V ● 0.93 1.00 1.07 A
CCFL High-Side Sense Servo Current BAT = 5V to 30V, I
CCFL
= 100µA, 0.1 0.16 %/V
Line Regulation I
VC
= 0µA at CCFL V
C
= 1.5V
CCFL High-Side Sense Supply Current Current Measured into BAT and Royer Pins ● 50 100 150 µA
Bulb Protect Servo Voltage I
CCFL
= 100µA, I
VC
= 0µA at CCFL V
C
= 1.5V, ● 6.5 7.0 7.5 V
Servo Voltage Measured Between BAT and Bulb Pins
Bulb Input Bias Current I
CCFL
= 100µA, I
VC
= 0µA at CCFL V
C
= 1.5V 5 9 µA
I
LIM1
CCFL Switch Current Limit Duty Cycle = 50% ● 1.25 1.9 3.0 A
Duty Cycle = 75% (Note 3)
● 0.9 1.6 2.6 A
V
SAT1
CCFL Switch On-Resistance CCFL I
SW
= 1A ● 0.6 1.0 Ω
∆I
Q
Supply Current Increase During CCFL I
SW
= 1A 20 30 mA/A
∆I
SW1
CCFL Switch On-Time
V
REF
Reference Voltage Measured at REF (Pin 11) on LT1183/LT1184/LT1184F 1.224 1.244 1.264 V
● 1.214 1.244 1.274 V
Reference Output Impedance Measured at REF (Pin 11) on LT1183 ● 20 45 70 Ω
Measured at REF (Pin 11) on LT1184/LT1184F
● 51530 Ω
ELECTRICAL CHARACTERISTICS
T
A
= 25°C, V
IN
= 5V, BAT = Royer = Bulb = 12V, I
CCFL
= SHUTDOWN = CCFL V
SW
= Open, DIO = GND, CCFL V
C
= 0.5V,
(LT1182/LT1183) LCD V
C
= 0.5V, LCD V
SW
= Open, (LT1182) FBN = FBP = GND, (LT1183) FB = GND,
(LT1183/LT1184/LT1184F) REF = Open, unless otherwise specified.