LT1768 Datasheet, PDF (2/20 Pages) Linear Technology – High Power CCFL Controller for Wide Dimming Range and Maximum Lamp Lifetime

LT1768
ABSOLUTE AXI U RATI GS
(Note 1)
Input Voltage (V_IN Pin) ............................................ 28V
SHDN Pin Voltage .................................................... 28V
FAULT Pin Voltage ................................................... 28V
PROG Pin Voltage ................................................... 5.5V
PWM Pin Voltage .................................................... 4.5V
C_T Pin Voltage ........................................................ 4.5V
SENSE Pin Voltage .................................................... 1V
DIO1, DIO2 Input Current ................................... ±50mA
R_MAX Pin Source Current ..................................... 750µA
R_MIN Pin Source Current ..................................... 750µA
V_REF Pin Source Current ....................................... 10mA
Operating Junction Temperature Range
LT1768C ................................................ 0°C to 125°C
LT1768I ............................................ – 40°C to 125°C
Storage Temperature Range ................. – 65°C to 150°C
Lead Temperature (Soldering 10 sec)................... 300°C
UW U
PACKAGE/ORDER I FOR ATIO
PGND 1
DI01 2
DI02 3
SENSE 4
VC 5
AGND 6
C_T 7
PROG 8
TOP VIEW
16 GATE
15 V_IN
14 V_REF
13 FAULT
12 SHDN
11 R_MIN
10 R_MAX
9 PWM
GN PACKAGE
16-LEAD PLASTIC SSOP
T_JMAX = 125°C, θ_JA = 100°C/W
ORDER PART
NUMBER
LT1768CGN
LT1768IGN
GN PART
MARKING
1768
1768I
Consult LTC Marketing for parts specified with wider operating temperature ranges.
ELECTRICAL CHARACTERISTICS The q denotes the specifications which apply over the full operating
temperature range, otherwise specifications are at T_A = 25°C, V_VIN = 12V, I_DIO1/2 = 250µA, V_PROG = 0V, V_PWM = 2.5V, I_RMAX = –100µA,
I_RMIN = –100µA, unless otherwise specified.
SYMBOL
I_Q
I_SHDN
V_REF
V_RMAX
V_RMIN
FSW
I_PROG
V_PROG
PARAMETER
Supply Current
Supply Current in Shutdown
SHDN Pin Pull-Up Current
SHDN Threshold Voltage
SHDN Threshold Hysteresis
V_IN Undervoltage Lockout
V_IN Undervoltage Lockout
REF Voltage
REF Line Regulation
REF Load Regulation
R_MAX Pin Voltage
R_MIN Pin Voltage
Switching Frequency
Maximum Duty Cycle
Minimum ON Time
PROG Pin Input Bias Current
PROG Pin Voltage for Zero Lamp Current
PROG Pin Voltage for Minimum Lamp Current
PROG Pin Voltage for Maximum Lamp Current
CONDITIONS
MIN TYP MAX UNITS
9V< V_VIN < 24V
V_SHDN = 0V
V_SHDN = 0V
V_SHDN Off to On
q
7
8
mA
q
65
100
µA
q4
7
12
µA
q 0.6
1.26
1.8
V
q 100
200
300
mV
V_IN Off to On
q 7.2
7.9
8.2
V
V_IN On to Off
q 7.1
7.4
7.6
V
I_REF = –1mA
q 4.9
5
5.1
V
∆V_VIN 8V to 24V I_REF = –1mA
q
7
20
mV
∆I_REF –1mA to –10mA
q
10
20
mV
q 1.225 1.25 1.275
V
q 1.22 1.26 1.30
V
V_PROG = 0.75V, V_SENSE = 0V
q 300
350
410
kHz
V_PROG = 0.75V, V_SENSE = 0V
93
%
V_PROG = 0.75V, V_SENSE = 150mV
125
ns
V_PROG = 5V
q
100
500
nA
(Note 2)
q 0.45
0.5
0.55
V
(Note 3)
(Note 4)
q 0.9
1
1.1
V
q 3.8
4
4.2
V
2