MAX1917EEE Maxim Integrated Products, MAX1917EEE Datasheet - Page 8

• Manufacturer Part Number: MAX1917EEE
• Description: Other Power Management
• Manufacturer: Maxim Integrated Products

Specifications of MAX1917EEE

• Case: ssop
• Dc: 03+
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Tracking, Sinking and Sourcing, Synchronous Buck
Controller for DDR Memory and Termination Supplies
(V+ = 12V, V
8
PIN
_______________________________________________________________________________________
10
11
12
13
14
15
16
1
2
3
4
5
6
7
8
9
OUT
EN/HSD
NAME
PGND
FSEL
VTTR
GND
DDR
POK
ILIM
VTT
REF
BST
DH
V+
DL
VL
LX
= 1.25V, T
18
16
14
12
10
8
6
4
2
0
Enable/High-Side Drain. Connect to the high-side N-FET drain for normal operation. Leave unconnected or
connect to GND for low-power shutdown.
DDR Reference Input. An applied voltage at DDR sets V
from 0 to 3.6V.
Power-OK Output. POK is an open-drain output and is logic high when both VTT and VTTR are within 12%
of regulation. POK is pulled low in shutdown.
VTT Feedback Input. Connect to VTT output.
Current-Limit Threshold Adjustment. Connect a resistor from ILIM to GND to set the current-limit threshold,
or connect ILIM to VL for default setting. See the Setting the Current Limit section.
Frequency Select. Selects the switching frequency of the MAX1917. See Table 1 for configuration of FSEL.
Reference Bypass. Connect a 0.22µF or larger capacitor from REF to GND.
Ground
VTTR Reference Output. Connect a 1µF or larger capacitor from VTTR to GND. VTTR is capable of
sourcing and sinking up to 25mA.
Input Supply Voltage. Supply input for the VL regulator and the VTTR regulator. Bypass with a 0.22µF or
larger capacitor.
Internal Regulator Output. Connect a 2.2µF or larger capacitor from VL to GND. VL can be connected to
V+ if the operating range is 4.5V to 5.5V.
Low-Side MOSFET Gate Drive. Connect to the gate of the low-side N-channel MOSFET.
Power Ground
Bootstrapped Supply to Drive High-Side N-Channel MOSFET. Connect a 0.47µF or larger capacitor from
BST to LX.
High-Side MOSFET Gate Drive. Connect to the high-side N-channel MOSFET gate.
Inductor Switching Node
-40
A
CURRENT LIMIT vs. TEMPERATURE
= +25°C, unless otherwise noted.)
R
-20
ILIM
R
ILIM
= 200kΩ
0
= 402kΩ
TEMPERATURE (°C)
20
40
Typical Operating Characteristics (continued)
60
80
100
18
16
14
12
10
8
INDUCTOR PEAK AND VALLEY CURRENT
1
vs. INPUT VOLTAGE AT CURRENT LIMIT
FUNCTION
CIRCUIT OF FIGURE 3
R
ILIM
3
= 400kΩ
I
VALLEY
VTT
5
and V
I
PEAK
7
V
IN
(V)
VTTR
9
11
to 1/2V
13
DDR
15
Pin Description
. DDR voltage range is