MAX797H Maxim, MAX797H Datasheet - Page 4

• Manufacturer Part Number: MAX797H
• Description: High-Voltage / Step-Down Controller with Synchronous Rectifier for CPU Power
• Manufacturer: Maxim

High-Voltage, Step-Down Controller with
Synchronous Rectifier for CPU Power
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 15V, GND = PGND = 0V, I VL = I REF = 0A, T
4
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 can increase due to excess PNP base current in the VL linear
Note 3: All -40°C to +85°C specifications are guaranteed by design.
Note 4: The power input is the high-side MOSFET drain.
+3.3V and +5V STEP-DOWN CONTROLLERS
FLYBACK/PWM CONTROLLER
INTERNAL REGULATOR AND REFERENCE
OSCILLATOR AND INPUTS/OUTPUTS
Input Supply Range
5V Output Voltage (CSL)
3.3V Output Voltage (CSL)
Nominal Adjustable Output
Voltage Range
Feedback Voltage
Line Regulation
Current-Limit Voltage
VL Output Voltage
VL Fault Lockout Voltage
VL/CSL Switchover Voltage
Reference Output Voltage
Reference Load Regulation
V+ Shutdown Current
V+ Off-State Leakage Current
Quiescent Power Consumption
Oscillator Frequency
SYNC High Pulse Width
SYNC Low Pulse Width
Oscillator Sync Range
Maximum Duty Factor
DL On-Resistance
DH On-Resistance
_______________________________________________________________________________________
regulator. This occurs only if V+ falls below the preset VL regulation point (5V nominal).
PARAMETER
V+
High-side MOSFET drain
0mV < (CSH - CSL) < 80mV, FB = VL,
6V < power input < 40V, includes line and load
regulation (Note 4)
0mV < (CSH - CSL) < 80mV, FB = 0V,
4.5V < power input < 40V, includes line and load
regulation (Note 4)
External resistor divider
CSH - CSL = 0V
FB = VL, 6V < power input < 40V (Note 4)
FB = 0V, 4.5V < power input < 40V (Note 4)
CSH - CSL, positive
CSH - CSL, negative
SHDN = 2V, 0mA < I
Rising edge, hysteresis = 15mV
Rising edge, hysteresis = 25mV
No external load (Note 1)
0µA < I
SHDN = 0V, V+ = 30V, CSL = 0V or 6V
FB = CSH = CSL = 6V, VL switched over to CSL
CSH = CSL = 6V
SYNC = REF
SYNC = 0V or 5V
SYNC = REF
SYNC = 0V or 5V
High or low
High or low, BST - LX = 4.5V
REF
< 100µA
A
= -40 to +85°C, SYNC = 0V, unless otherwise noted.) (Note 3)
VL
CONDITIONS
< 25mA, 5.5V < V+ < 30V
4.70
3.10
2.40
3.75
2.43
MIN
REF
250
120
250
250
210
5.0
-40
4.7
4.2
70
89
93
2.505
-100
TYP
5.10
3.35
0.04
0.04
300
150
4.8
91
96
1
1
MAX
5.40
3.56
2.60
0.06
0.06
-160
4.15
2.57
130
350
180
320
6.0
5.3
4.7
8.4
30
40
50
10
10
7
7
UNITS
%/V
%/V
mW
kHz
kHz
mV
mV
µA
µA
ns
ns
%
Ω
Ω
V
V
V
V
V
V
V
V
V