Electrical characteristics (continued) – Rainbow Electronics MAX1774 User Manual
Page 6
MAX1774
Dual, High-Efficiency, Step-Down
Converter with Backup Battery Switchover
6
_______________________________________________________________________________________
PARAMETER
SYMBOL
CONDITIONS
MIN
MAX
UNITS
CORE REGULATOR
Input Voltage Range
V
INC
2.6
5.5
V
V
INC
rising
2.39
2.55
INC Undervoltage Lockout
V
INC
falling
2.29
2.45
V
Core Output Voltage Adjust
Range
1.0
5.0
V
Maximum Core Load Current
V
CORE
= 1.8V (Note 1)
1
A
FBC Regulation Threshold
V
FBC
V
INC
= +2.5 to +5.5V,
I
OUTC
= 0 to 200mA
0.97
1.03
V
FBC Input Current
I
FBC
V
FBC
= +1.3V
-0.1
0.1
µA
Dropout Voltage
I
OUTC
= 400mA
0.25
V
LXC Leakage Current
I
LXC
V
INC
= +5.5V, V
LXC
= 0 to +5.5V
-10
10
µA
LXC P-Channel, N-Channel
On-Resistance
0.5
Ω
LXC P-Channel Current Limit
1200
3010
mA
LXC P-Channel Minimum
Current
100
420
mA
LXC N-Channel Valley Current
880
2450
mA
LXC N-Channel Zero-Crossing
Current
40
170
mA
Max Duty Cycle
100
%
Minimum On-Time
160
700
ns
Minimum Off-Time
170
690
ns
BACKUP REGULATOR
Backup Battery Input Voltage
V
BBATT
0.9
5.5
V
LXB N-Channel On Resistance
V
CS-
= +3.3V, I
LXB
= 50mA
3.5
Ω
LXB Current Limit
200
600
mA
LXB Leakage Current
V
LXB
= +5.5V, V
FBM
= +1.3V
1
µA
BIN Leakage Current
I
BIN
V
BIN
= +5.5V, CS- = BKOFF =
SHDNC = SHDNM = GND
1
µA
BIN, CS- Switch Resistance
V
CS-
= +3.3V, BKOFF = GND,
SHDNC = CVL
15
Ω
BIN Switch Zero-Crossing
Threshold
V
BIN
= +2.5V, BKOFF = SHDNC =
SHDNM = CVL
35
mV
LXB Maximum On-Time
2.8
9.2
µs
REFERENCE
Reference Voltage
V
REF
1.220
1.275
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
ELECTRICAL CHARACTERISTICS (continued)
(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)