MAX8550-MAX8551 MAXIM [Maxim Integrated Products], MAX8550-MAX8551 Datasheet - Page 11

• Manufacturer Part Number: MAX8550-MAX8551
• Description: Integrated DDR Power-Supply Solutions for Desktops, Notebooks, and Graphic Cards
• Manufacturer: MAXIM [Maxim Integrated Products]

Figure 1. Functional Diagram
(N.C. IN MAX8551)
*POWER-DOWN
FORCES POK2 LOW
AND VTT, VTTR TO
HIGH IMPEDANCE.
Integrated DDR Power-Supply Solutions for
OVP/UVP
SHDNA
SHDNB
STBY
POK1
POK2
TON
FB
Desktops, Notebooks, and Graphic Cards
______________________________________________________________________________________
VTT ON/OFF
BUCK ON/OFF
SHUTDOWN
N
DECODER
N
VTTR ON/OFF
REFIN / 2 - 10%
REFIN / 2 - 10%
BIAS ON/OFF
INTREF + 10%
QUAD LEVEL
DECODE
0.7 x INTREF
TRIG
COMPUTE
ONE-SHOT
ON-TIME
REFIN / 2 + 10%
REFIN / 2 + 10%
IN
1.16 x INTREF
t
ON
INTREF - 10%
OVP/UVP
LATCH
Q
TIMER
20ms
OUT
INTREF
POWER-DOWN*
CURRENT
LIMITS
SS
+0.4V
V
VTT ILIM
VTTR ILIM
OUT
= 2.5V
S
R
V
OUT
DECODE
Q
FB
= 1.8V
LX
S
R
ONE-SHOT
Q
t
1.0V
OFF
Q
ZERO CROSSING
INTREF
PGND2
TRIG
VTTI
DISCHARGE
LOGIC
10kΩ
V
V
DD
DD
REFERENCE
REFIN / 2
MAX8550/
MAX8551
2V
10kΩ
N
N
LX
V
DD
N
- 1V
BST
DH
LX
V
DL
PGND
ILIM
SKIP
(TP1 IN MAX8551
MUST BE CONNECTED TO GND)
OUT
AV
GND
REF
VTTS
REFIN
VTTI
VTT
PGND2
VTTR
DD
DD
11