Rainbow Electronics MAX1839 - Manual (Page 5)

MAX1739/MAX1839
†
Wide Brightness Range
CCFL Backlight Controllers
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ELECTRICAL CHARACTERISTICS
(V+ = 8.2V, V SH /SUS = V SH = 5.5V, MINDAC = GND, T A = -40°C to +85°C, unless otherwise noted.) (Note 6)
PARAMETER CONDITIONS MIN TYP MAX UNITS
SUPPLY AND REFERENCE
VL = V
BATT
4.6 5.5
V BATT Input Voltage Range
VL = open 6 28
V
V BATT Quiescent Current, Shutdown SH/SUS = SH = GND 20 µA
VL Output Voltage, Normal Operation
6V < V BATT < 28V,
0 < I
LOAD < 15mA
5.0 5.6 V
VL rising (leaving lockout) 4.6
VL Undervoltage Lockout Threshold
VL falling (entering lockout) 4.0
V
REF Output Voltage, Normal
Operation
4.5V < VL < 5.5V, I REF = 40µA 1.95 2.05 V
VL POR Threshold 0.9 2.7 V
SWITCHING REGULATOR
DH Driver On-Resistance 18 Ω
DL1, DL2 Driver On-Resistance 18 Ω
SYNC Synchronization Range Detect falling edges on SYNC 64 200 kHz
CS Overcurrent Threshold 408 492 mV
DAC AND ERROR AMPLIFIER
CSAV Regulation Point V MINDAC = 0, DAC code = 11111 binary 186 202 mV
CTFB Regulation Point 560 640 mV
CTFB to CCV Transconductance 1V < V CCV < 2.7V 30 50 µmho
ANALOG INTERFACE BRIGHTNESS CONTROL (MODE connected to REF or MODE connected to GND)
SH Input Low Voltage 0.8 V
SH Input High Voltage 2.1 V
SYSTEM MANAGEMENT BUS BRIGHTNESS CONTROL (MODE connected to VL)
CRF/SDA, CTL/SCL, SH/SUS Input
Low Voltage
0.8 V
CRF/SDA, CTL/SCL, SH/SUS Input
High Voltage
2.1 V
CRF/SDA Output Low Sink Current V CRF/SDA = 0.4V 4 mA
Note 1: Corresponds to 512 DPWM cycles or 65536 MODE
cycles.
Note 2: When the buck switch is shorted, V CTFB goes high
causing V CCV to go below the fault detection threshold.
Note 3: Corresponds to 64 DPWM cycles or 8192 MODE cycles.
Note 4: The MODE pin thresholds are only valid while the part is
operating. In shutdown, V REF = 0 and the part only
differentiates between SMB mode and ADC mode. In
shutdown with ADC mode selected, the CRF/SDA and
CTL/SCL pins are at high impedance and will not cause
extra supply current when their voltages are not at
GND or VL.
V AMPLITUDE > 2V
MODE
500pF
10k
Note 5: The amplitude is measured with the following circuit:
Note 6: Specifications from -40°C to +85°C are guaranteed by
design, not production tested.