MAX798 Maxim, MAX798 Datasheet - Page 4

• Manufacturer Part Number: MAX798
• Description: High-Accuracy Step-Down Controller with Synchronous Rectifier for CPU Power
• Manufacturer: Maxim

High-Accuracy Step-Down Controller
with Synchronous Rectifier for CPU Power
ELECTRICAL CHARACTERISTICS
(V+ = +15V, GND = PGND = 0V, I
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 above are guaranteed by design.
STEP-DOWN CONTROLLER
Input Supply Range
Nominal Adjustable Output
Voltage Range
Feedback Voltage
Load Regulation
Line Regulation
Current-Limit Voltage
INTERNAL REGULATOR AND REFERENCE
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 AND INPUTS/OUTPUTS
Oscillator Frequency
SYNC High Pulse Width
SYNC Low Pulse Width
Oscillator Sync Range
Maximum Duty Cycle
DL On-Resistance
DH On-Resistance
_______________________________________________________________________________________
regulator. This occurs only if V+ falls below the preset VL regulation point (5V nominal). The typical maximum quiescent
current in dropout will not exceed 16mA.
PARAMETER
VL
External resistor divider
CSH - CSL = 40mV, SKIP = VL
0mV < (CSH - CSL) < 80mV, SKIP = VL
6V < V+ < 30V
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
= I
REF
REF
= 0A, T
< 100µA
A
= -40°C to +85°C, unless otherwise noted.) (Note 3)
VL
CONDITIONS
< 25mA, 5.5V < V+ < 30V
1.560
2.438
3.75
4.15
MIN
250
110
250
250
210
5.0
1.6
-40
4.7
70
88
92
2.505
TYP
0.04
-100
300
150
1.6
6.4
91
96
1
1
1.640
2.562
MAX
-160
0.06
4.05
4.75
130
350
190
320
6.0
5.3
9.1
±1
30
30
10
10
7
7
UNITS
%/ V
mW
kHz
kHz
mV
mV
µA
µA
ns
ns
%
%
Ω
Ω
V
V
V
V
V
V
V