Rainbow Electronics MAX1774 - Manual (Page 4)

MAX1774
Dual, High-Efficiency, Step-Down
Converter with Backup Battery Switchover
4 _______________________________________________________________________________________
PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS
REFERENCE
Reference Voltage V REF 1.23 1.25 1.27 V
Reference Load Regulation I
REF
= 0 to 50µA 10 mV
Reference Line Regulation V CS- = +2.5V to +5.5V, I REF = 50µA 5 mV
Reference Sink Current 10 µA
CVL, CVH REGULATORS
I CVL = 50mA, V CS- = 0 2.6 2.8 3.1
CVL Output Voltage V CVL
I CVL = 50mA, V CS- = +3.3V 3.2
V
CVL Switchover Threshold CS- rising, hysteresis = 100mV typical 2.40 2.47 2.55 V
V IN = +4V, I CVH = 25mA
V IN -
3.4
V IN -
2.8
CVH Output Voltage V CVH
V IN = +12V, I CVH = 50mA
V IN -
4.2
V IN -
3.7
V
CVH Switchover Threshold V
IN
V
IN
rising, hysteresis = 350mV typ 5.5 V
V CVL rising 2.40 2.47 2.55
CVL Undervoltage Lockout
V CVL falling 2.30 2.37 2.45
V
LOW-VOLTAGE COMPARATORS
V BKOFF rising 0.51 0.55 0.59 Backup Regulator Shutdown
Threshold
V BKOFF
V BKOFF falling 0.46 0.50 0.54
V
BKOFF Input Bias Current V BKOFF = +5.5V 1 µA
LBI Threshold V LBI V LBI falling, hysteresis = 50mV typical 1.17 1.20 1.23 V
DBI Threshold V DBI V DBI falling, hysteresis = 50mV typical 1.17 1.20 1.23 V
BKUP Low-Input Threshold 0.4 V
LBI, DBI Input Leakage Current V LBI = V DBI = +1.3V 100 nA
LBO, BKUP, ACO, MDRV
Output Low
I SINK = 1mA 0.4 V
LBO, BKUP, ACO, MDRV
Output Leakage Current V LBI = +1.3V, V ACI = +12V, V ACO =
V LBO = V BKUP = +5.5V, V MDRV = +28V
1.0 µA
ACI Threshold V ACI – V INS, ACI falling 0.22 0.35 V
ACI Input Leakage Current V ACI = +1.3V 100 nA
INS Input Leakage Current V INS = +3.3V 1.5 10 µA
LOGIC INPUTS
SHDNM, SHDNC Input Low
Voltage
0.4 V
SHDNM, SHDNC Input High
Voltage
2.0 V
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.)