Datasheet

MAX796/MAX797/MAX799
Step-Down Controllers with
Synchronous Rectifier for CPU Power
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 15V, GND = PGND = 0V, I
VL
= I
REF
= 0A, T
A
= -40°C to +85°C for MAX79_E, unless otherwise noted.) (Note 3)
Note 3: All -40°C to +85°C specifications above are guaranteed by design.
External resistor divider
0mV < (CSH - CSL) < 80mV, FB = VL, 4.5V < V+ < 30V,
includes line and load regulation
0mV < (CSH - CSL) < 80mV, FB = VL, 6V < V+ < 30V,
includes line and load regulation
CONDITIONS
VREF 6.0
Nominal Adjustable Output
Voltage Range
V3.10 3.35 3.563.3V Output Voltage (CSL)
V5.0 30Input Supply Range
V4.70 5.10 5.405V Output Voltage (CSL)
UNITSMIN TYP MAXPARAMETER
CSH - CSL, negative
(CSH-CSL) = 0V
6V < V+ < 30V
CSH - CSL, positive
-40 -100 -160
Current-Limit Voltage
V2.40 2.60Feedback Voltage
%/V0.04 0.06Line Regulation
mV
70 130
FB = CSH = CSL = 6V, VL switched over to CSL
SHDN = 0V, V+ = 30V, CSL = 0V or 6V
Rising edge, hysteresis = 25mV
No external load (Note 1)
0µA < I
REF
< 100µA
µA110V+ Off-State Leakage Current
µA110V+ Shutdown Current
V
Rising edge, hysteresis = 15mV
SHDN = 2V, 0mA < I
VL
< 25mA, 5.5V < V+ < 30V
4.2 4.7VL/CSL Switchover Voltage
V2.43 2.505 2.57Reference Output Voltage
Falling edge, hysteresis = 15mV (MAX796)
Falling edge, hysteresis = 20mV (MAX799)
mV50Reference Load Regulation
V3.75 4.05VL Fault Lockout Voltage
V4.7 5.3VL Output Voltage
2.40 2.60
V
-0.08 0.08
SECFB Regulation Setpoint
SYNC = REF
SYNC = 0V or 5V
89 91
kHz210 320Oscillator Sync Range
kHz
SYNC = REF
120 150 180
Oscillator Frequency
ns250SYNC High Pulse Width
ns250SYNC Low Pulse Width
250 300 350
mW4.8 8.4Quiescent Power Consumption
High or low, BST - LX = 4.5V
High or low
SYNC = 0V or 5V
Ω7DH On-Resistance
Ω7DL On-Resistance
%
93 96
Maximum Duty Cycle
+3.3V and +5V STEP-DOWN CONTROLLERS
FLYBACK/PWM CONTROLLER
INTERNAL REGULATOR AND REFERENCE
OSCILLATOR AND INPUTS/OUTPUTS