Datasheet

MAX1917
Tracking, Sinking and Sourcing, Synchronous Buck
Controller for DDR Memory and Termination Supplies
4 _______________________________________________________________________________________
ELECTRICAL CHARACTERISTICS (continued)
(V+ = 12V, V
EN/HSD
= V
DDR
= 2.5V, C
VL
= 4.7µF, C
VTTR
= 1µF, C
REF
= 0.22µF, V
FSEL
= 0, ILIM = VL, PGND = LX = POK = GND,
BST = VL. Specifications are for T
A
= 0°C to +85°C. Typical values are at T
A
= +25°C, unless otherwise specified.)
PARAMETER CONDITIONS MIN TYP MAX UNITS
Logic VL Level FSEL = VL VL - 0.4 V
EN/HSD LOGIC
EN/HSD Shutdown Current Max I
EN/HSD
for V
EN/HSD
= 0.8V 0.5 3.0 µA
Logic High VL = V+ = 4.5V to 5.5V, 100mV hysteresis 1.45 V
Logic Low VL = V+ = 4.5V to 5.5V 0.8 V
POWER-OK OUTPUT
Upper VTT Threshold 110 112 114
%V
DDR
/
2
Lower VTT Threshold 86 88 90
%V
DDR
/
2
Upper VTTR Threshold 110 112 114
%V
DDR
/
2
Lower VTTR Threshold 86 88 90
%V
DDR
/
2
POK Output Low Level I
SINK
= 2mA 0.4 V
POK Output High Leakage V
POK
= 5.5V 5 µA
ELECTRICAL CHARACTERISTICS
(V+ = 12V, V
EN/HSD
= V
DDR
= 2.5V, C
VL
= 4.7µF, C
VTTR
= 1µF, C
REF
= 0.22µF, V
FSEL
= 0, ILIM = VL, PGND = LX = POK = GND,
BST = VL. Specifications are for T
A
= -40°C to +85°C, unless otherwise specified.) (Note 2)
PARAMETER CONDITIONS MIN TYP MAX UNITS
5.5 14.0 V
V+ Input Voltage Range
VL = V+ 4.5 5.5 V
EN/HSD Input Voltage Range Enabled 1.5 15.0 V
DDR Input Voltage Range 0 3.6 V
V+ Supply Current VTT = 2.0V 1.2 mA
DDR Supply Current 250 µA
EN/HSD Supply Current V
EN/HSD
= 2.5V 10 µA
VL Supply Current VL = V+ = 5.5V 1.2 mA
V+ Shutdown Supply Current EN/HSD = 0V 5 µA
DDR Shutdown Supply Current EN/HSD = 0V 1 µA
VL Shutdown Supply Current VL = V+ = 5.5V 5 µA
VL Undervoltage Lockout
Threshold
Rising edge, hysteresis = 40mV 4.05 4.40 V
VTT
VTT Input Bias Current V
VTT
= 2.5V -0.15 0 µA
VTT Feedback Voltage Range 0 1.8 V
Overload range, V
DDR
= 1.8V 49.5 50.5
VTT Feedback Voltage
Accuracy
Overload range, V
DDR
= 3.6V 49.5 50.5
%V
DDR
REFERENCE
Reference Output Voltage V+ = VL = 4.5V to 5.5V, I
REF
= 0 1.98 2.02 V
Reference Load Regulation V+ = VL = 5V, I
REF
= 0 to 50µA 10 mV