Step-Down Controllers with
Synchronous Rectifier for CPU Power
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 15V, GND = PGND = 0V, I = I
= 0A, T = -40°C to +85°C for MAX79_E, unless otherwise noted.) (Note 3)
A
VL REF
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
+3.3V and +5V STEP-DOWN CONTROLLERS
Input Supply Range
5.0
30
V
V
0mV < (CSH - CSL) < 80mV, FB = VL, 6V < V+ < 30V,
includes line and load regulation
5V Output Voltage (CSL)
3.3V Output Voltage (CSL)
4.70
5.10
3.35
5.40
0mV < (CSH - CSL) < 80mV, FB = VL, 4.5V < V+ < 30V,
includes line and load regulation
3.10
3.56
6.0
V
V
Nominal Adjustable Output
Voltage Range
External resistor divider
REF
2.40
Feedback Voltage
Line Regulation
(CSH-CSL) = 0V
6V < V+ < 30V
2.60
0.06
130
V
0.04
-100
%/V
CSH - CSL, positive
CSH - CSL, negative
70
Current-Limit Voltage
mV
V
-40
-160
FLYBACK/PWM CONTROLLER
SECFB Regulation Setpoint
Falling edge, hysteresis = 15mV (MAX796)
Falling edge, hysteresis = 20mV (MAX799)
2.40
2.60
0.08
-0.08
INTERNAL REGULATOR AND REFERENCE
VL Output Voltage
4.7
3.75
4.2
5.3
4.05
4.7
2.57
50
V
V
SHDN = 2V, 0mA < I < 25mA, 5.5V < V+ < 30V
VL
VL Fault Lockout Voltage
VL/CSL Switchover Voltage
Reference Output Voltage
Reference Load Regulation
V+ Shutdown Current
Rising edge, hysteresis = 15mV
Rising edge, hysteresis = 25mV
No external load (Note 1)
V
2.43
2.505
V
0µA < I
< 100µA
mV
µA
µA
mW
REF
1
1
10
SHDN = 0V, V+ = 30V, CSL = 0V or 6V
V+ Off-State Leakage Current
Quiescent Power Consumption
FB = CSH = CSL = 6V, VL switched over to CSL
10
4.8
8.4
OSCILLATOR AND INPUTS/OUTPUTS
SYNC = REF
250
120
250
250
210
89
300
150
350
180
Oscillator Frequency
kHz
SYNC = 0V or 5V
SYNC High Pulse Width
SYNC Low Pulse Width
Oscillator Sync Range
ns
ns
320
kHz
SYNC = REF
91
96
Maximum Duty Cycle
%
SYNC = 0V or 5V
High or low
93
DL On-Resistance
DH On-Resistance
7
7
Ω
Ω
High or low, BST - LX = 4.5V
Note 3: All -40°C to +85°C specifications above are guaranteed by design.
4
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
