Rainbow Electronics MAX1774 - Manual (Page 5)

MAX1774
Dual, High-Efficiency, Step-Down
Converter with Backup Battery Switchover
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PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
SHDNM, SHDNC Input Low
Current
SHDNM = SHDNC = GND -1 1 µA
SHDNC Input High Current V SHDNC = +5.5V 5 µA
SHDNM Input High Current V SHDNM = +5V 2 25 µA
ELECTRICAL CHARACTERISTICS
(Figure 1, V
IN
= V
INS
= +12V, V
INC
= V
CS-
= V
CS+
= +3.3V, V
CORE
= +1.8V, T
A
= -40°C to +85°C, unless otherwise noted.) (Note 2)
PARAMETER SYMBOL CONDITIONS MIN MAX UNITS
Input Voltage V IN 2.7 28 V
Input Quiescent Supply Current I IN
V FBM = +1.5V, V FBC = +1.5V, V SHDNM =
V SHDNC = +3.3V
40 µA
CS- Quiescent Supply Current I CS-
V FBM = +1.5V, V FBC = +1.5V, V SHDNM =
V SHDNC = +3.3V
220 µA
Core Regulator Quiescent
Supply Current
I INC
V FBM = +1.5V, V FBC = +1.5V, V SHDNM =
V SHDNC = +3.3V
105 µA
Backup Mode BIN Quiescent
Supply Current
I BIN
V BIN = +3.3V, CS- open
V FBM = +1.5V, V SHDNM = +3.3V,
V BKOFF = +1.5V, SHDNC = GND
110 µA
IN Shutdown Supply Current SHDNM = SHDNC = GND 40 µA
MAIN REGULATOR
Main Output Voltage Adjust
Range
1.25 5.5 V
FBM Regulation Threshold V
FBM
V (CS+ - CS-) = 0 to +60mV,
V IN = +3.5V to +28V
1.21 1.29 V
FBM Input Current I FBM V FBM = +1.3V -0.1 0.1 µA
Current-Limit Threshold V
CS+
- V
CS-
60 100 mV
Minimum Current-Limit
Threshold
V CS+ - V CS- 5 25 mV
Valley Current Threshold V CS+ - V CS- 40 60 mV
Zero Current Threshold V CS+ - V CS- 0 15 mV
PDRV, NDRV Gate Drive
Resistance
V
CS-
= +3.3V, I
PDRV
, I
NDRV
= 50mA 5.5 Ω
CS- to CVL Switch Resistance I CVL = 50mA 9.5
Ω
Maximum Duty Cycle 100 %
Minimum On-Time 200 650 ns
Minimum Off-Time 200 650 ns
ELECTRICAL CHARACTERISTICS (continued)
(Figure 1, V IN = V INS = +12V, V INC = V CS- = V CS+ = +3.3V, V CORE = +1.8V, T A = 0°C to +85°C, unless otherwise noted. Typical values are
at T A = +25°C.)