MAX1639 Datasheet, PDF (3/13 Pages) Maxim Integrated Products – High-Speed Step-Down Controller with Synchronous Rectification for CPU Power

High-Speed Step-Down Controller with
Synchronous Rectification for CPU Power
ELECTRICAL CHARACTERISTICS (continued)
(V_DD = V_CC = +5V, PGND = AGND = 0V, FREQ = REF, T_A = 0°C to +85°C, unless otherwise noted.)
PARAMETER
CONDITIONS
MIN
FREQ Input Current
CSH, CSL Input Current
CSH = CSL = 1.1V
FB Input Current
CC1 Output Resistance
CC2 Transconductance
Minimum
2.4
CC2 Clamp Voltage
Maximum
4
CC2 Source/Sink Current
30mV overdrive
DH On-Resistance
BST - LX = 4.5V
DL On-Resistance
DH, DL Source/Sink Current
V_DD = 4.5V
DH = DL = 2.5V
DH, DL Dead Time
0
FB = 1.1V
85
Current-Limit Trip Voltage
FB = 0V (foldback)
15
Soft-Start Time
To full current limit
BST Leakage Current
BST = 12V, LX = 7V, REF = GND
TYP
10
1
100
0.7
0.7
2
30
100
38
1536
MAX
4
50
±0.1
3.0
V_CC
2
2
115
70
50
UNITS
µA
µA
µA
kΩ
mmho
V
µA
Ω
Ω
A
ns
mV
1 / f_OSC
µA
ELECTRICAL CHARACTERISTICS
(V_DD = V_CC = +5V, PGND = AGND = 0V, FREQ = REF, T_A = -40°C to +85°C, unless otherwise noted.) (Note 1)
PARAMETER
Input Voltage Range
Input Undervoltage Range
V_DD Supply Current
CONDITIONS
MIN
V_CC = V_DD
4.5
V_CC rising edge, 1% hysteresis
3.9
V_CC = V_DD = ^{Operating mode FB overdrive = 60mV}
5.5V
Shutdown mode VREF = 0V
TYP
V_DD Supply Current
V_CC = V_DD = 5.5V, FB forced 60mV above
regulation point, operating or shutdown mode
Reference Voltage
FB Voltage
PWROK Trip Level
Switching Frequency
Maximum Duty Cycle
DH On-Resistance
DL On-Resistance
Current-Limit Trip Voltage
No load
Includes line and load regulation errors
Rising FB, 1% hysteresis with respect to V_REF
Falling FB, 1% hysteresis with respect to V_REF
FREQ = V_CC
FREQ = REF
FREQ = AGND
FREQ = V_CC
BST - LX = 4.5V
V_DD = 4.5V
FB = 1.1V
3.448
1.072
-8
6
800
510
240
84
70
MAX
5.5
4.3
3
12
0.2
3.553
1.128
-4
10
1200
690
360
2
2
130
UNITS
V
V
mA
mA
V
V
%
kHz
%
Ω
Ω
mV
Note 1: Specifications from 0°C to -40°C are guaranteed by design, not production tested.
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