High-Accuracy Step-Down Controller
with Synchronous Rectifier for CPU Power
MAX798
ABSOLUTE MAXIMUM RATINGS
V+ to GND .................................................................-0.3V, +36V
GND to PGND........................................................................±2V
VL to GND ...................................................................-0.3V, +7V
BST to GND ...............................................................-0.3V, +36V
DH to LX ........................................................-0.3V, (BST + 0.3V)
LX to BST.....................................................................-7V, +0.3V
SHDN
to GND............................................................-0.3V, +36V
SYNC, SS, REF,
SKIP,
DL to GND ...................-0.3V, (VL + 0.3V)
CSH, CSL to GND .......................................................-0.3V, +7V
VL Short Circuit to GND..............................................Momentary
REF Short Circuit to GND ...........................................Continuous
VL Output Current ...............................................................50mA
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 8.70mW/°C above +70°C) ........................696mW
Operating Temperature Range
MAX798ESE....................................................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V+ = +15V, GND = PGND = 0V, I
VL
= I
REF
= 0A, T
A
= 0°C to +85°C, unless otherwise noted.)
PARAMETER
STEP-DOWN CONTROLLER
Input Supply Range
Nominal Adjustable Output
Voltage Range
Feedback Voltage
Load Regulation
Line Regulation
Current-Limit Voltage
SS Source Current
SS Fault Sink Current
INTERNAL REGULATOR AND REFERENCE
VL Output Voltage
VL Fault Lockout Voltage
VL/CSL Switchover Voltage
Reference Output Voltage
Reference Fault Lockout Voltage
Reference Load Regulation
CSL Shutdown Leakage Current
V+ Shutdown Current
V+ Off-State Leakage Current
Dropout Power Consumption
Quiescent Power Consumption
SHDN
= 2V, 0mA <I
VL
< 25mA, 5.5V < V+ < 30V
Rising edge, hysteresis = 15mV
Rising edge, hysteresis = 25mV
No external load (Note 1)
Falling edge
0µA < I
REF
< 100µA
SHDN
= 0V, CSL = 6V, V+ = 0V or 30V, VL = 0V
SHDN
= 0V, V+ = 30V, CSL = 0V or 6V
FB = CSH = CSL = 6V, VL switched over to CSL
V+ = 4V, CSL = 0V (Note 2)
CSH = CSL = 6V
0.1
1
1
6.6
6.4
4.75
3.8
4.2
2.463
1.8
2.505
5.25
4.0
4.7
2.537
2.3
20
1
5
5
10.5
8.5
V
V
V
V
V
mV
µA
µA
µA
mW
mW
External resistor divider
CSH - CSL = 40mV,
SKIP
= VL
0mV < (CSH - CSL) < 80mV,
SKIP
= VL
6V < V+ < 30V
CSH - CSL, positive
CSH - CSL, negative
80
-40
2.0
2.0
0.04
100
-100
4.0
4.5
1.6
1.576
1.6
30
6
1.624
±0.4
0.05
120
-160
6.5
V
V
V
%
%/V
mV
µA
mA
CONDITIONS
MIN
TYP
MAX
UNITS
2
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MAXIM [ MAXIM INTEGRATED PRODUCTS ]
