Step-Down Controllers with
Synchronous Rectifier for CPU Power
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 15V, GND = PGND = 0V, I
= I
= 0A, T = 0°C to +70°C for MAX79_C, T = 0°C to +85°C for MAX79_E,
A A
REF
VL
= -55°C to +125°C for MAX79_M, unless otherwise noted.)
T
A
PARAMETER
Reference Output Voltage
CONDITIONS
MIN
2.46
2.45
1.8
TYP
2.505
MAX
2.54
2.55
2.3
50
1
UNITS
MAX79_C
No external load (Note 1)
V
MAX79_E/M
Reference Fault Lockout Voltage Falling edge
Reference Load Regulation 0µA < I < 100µA
CSL Shutdown Leakage Current SHDN = 0V, CSL = 6V, V+ = 0V or 30V, VL = 0V
V
mV
µA
REF
0.1
1
MAX79_C
3
SHDN = 0V, V+ = 30V,
CSL = 0V or 6V
V+ Shutdown Current
µA
µA
MAX79_E/M
MAX79_C
1
5
1
3
FB = CSH = CSL = 6V,
VL switched over to CSL
V+ Off-State Leakage Current
MAX79_E/M
1
5
Dropout Power Consumption
Quiescent Power Consumption
V+ = 4V, CSL = 0V (Note 2)
CSH = CSL = 6V
4
8
mW
mW
4.8
6.6
OSCILLATOR AND INPUTS/OUTPUTS
SYNC = REF
270
125
200
200
300
150
330
175
Oscillator Frequency
kHz
SYNC = 0V or 5V
SYNC High Pulse Width
SYNC Low Pulse Width
SYNC Rise/Fall Time
Oscillator Sync Range
ns
ns
Guaranteed by design
200
340
ns
190
89
kHz
SYNC = REF
SYNC = 0V or 5V
SYNC
91
96
Maximum Duty Cycle
Input High Voltage
Input Low Voltage
%
V
93
VL - 0.5
2.0
SHDN, SKIP
SYNC
0.8
0.5
2.0
0.1
1.0
50
V
SHDN, SKIP
SHDN, 0V or 30V
SECFB, 0V or 4V
SYNC, SKIP
µA
Input Current
CSH, CSL, CSH = CSL = 6V, device not shut down
FB, FB = REF
100
nA
A
DL Sink/Source Current
DH Sink/Source Current
DL On-Resistance
DL forced to 2V
1
1
DH forced to 2V, BST-LX = 4.5V
High or low
A
7
7
Ω
Ω
DH On-Resistance
High or low, BST-LX = 4.5V
Note 1: Since the reference uses VL as its supply, V+ line-regulation error is insignificant.
Note 2: At very low input voltages, quiescent supply current may increase due to excess PNP base current in the VL linear
regulator. This occurs only if V+ falls below the preset VL regulation point (5V nominal). See the Quiescent Supply Current
vs. Supply Voltage graph in the Typical Operating Characteristics.
_______________________________________________________________________________________
3
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
