Datasheet

MAX8855/MAX8855A
Dual, 5A, 2MHz Step-Down Regulators
_______________________________________________________________________________________ 3
PARAMETER CONDITIONS MIN TYP MAX UNITS
ERROR AMPLIFIER
V
V D D
= V
I N _
= 2.5V to
3.3V ( M AX 8855)
FB_ Regulation Voltage
V
C OM P _
= 1V to
2V
V
V D D
= V
I N _
= 2.25V to
3.3V ( M AX 8855A)
0.594 0.600 0.606 V
V
V D D
= V
I N _
= 2.5V to
3.3V ( M AX 8855)
FB_ Regulation Voltage with External
Reference
V
C OM P _
= 1V to
2V
V
V D D
= V
I N _
= 2.25V to
3.3V ( M AX 8855A)
0.594 0.600 0.606 V
Error Amplifier Common-Mode-Input Range 0
V
VDD
-
1.6
V
Error Amplifier Maximum Output Current 1 mA
T
A
= +25°C 40 300
FB_ Input Bias Current V
FB_
= 0.605V
T
A
= +85°C 37
nA
REFIN, SS2
T
A
= +25°C 90 500
REFIN Input Bias Current V
FB
_ = 0.610V
T
A
= +85°C65
nA
MAX8855 V
VDD
= 2.35V to 2.6V
MAX8855A
V
VDD
= 2.25V to 2.6V
0
V
VDD
-
1.65
REFIN Common-Mode Range
V
VDD
= 2.6V to 3.6V 0
V
VDD
-
1.70
V
LX1, LX2 (ALL PINS COMBINED)
V
IN
_
= V
BS T
_
- V
LX
_
= 3.3V 31 52
LX_ On-Resistance, High I
LX_
= -2A
V
IN
_
= V
BS T
_
- V
LX
_
= 2.5V 34
mΩ
V
IN _
= 3.3V 27 46
LX_ On-Resistance, Low I
LX_
= -2A
V
IN _
= 2.5V 29
mΩ
LX_ Current-Limit Threshold High-side sourcing and freewheeling 7.0 8.3 9.6 A
T
A
= +25°C +0.1
V
LX_
= 3.6V
T
A
= +85°C-0.1
T
A
= +25°C -10
LX_ Leakage Current
V
IN_
= 3.6V,
V
EN_
= 0V
V
LX_
= 0V
T
A
= +85°C-0.1
μA
R
FSYNC
= 10kΩ 0.9 1.0 1.1
LX_ Switching Frequency
R
FSYNC
= 4.75kΩ 1.80 2.0 2.2
MHz
LX_ Minimum Off-Time 50 ns
LX_ Minimum On-Time 95 ns
LX_ Maximum Duty Cycle R
FSYNC
= 10kΩ 90 95 %
Maximum LX_ Output Current 3 A
RMS
ELECTRICAL CHARACTERISTICS (continued)
(V
IN_
= V
VDD
= V
VDL
= 3.3V, V
FB_
= 0.5V, V
SS_
= V
REFIN
= 600mV, PGND_ = GND, R
FSYNC
= 10kΩ, L = 0.47μH, C
BST_
= 0.1μF,
C
SS_
= 0.022μF, PWRGD_ not connected; T
A
= -40°C to +85°C, typical values are at T
A
= +25°C, unless otherwise noted.) (Note 2)