MAX8550AETI+ Maxim Integrated Products, MAX8550AETI+ Datasheet - Page 24

• Manufacturer Part Number: MAX8550AETI+
• Description: IC PWR SUP DDR INTEG 28TQFN
• Manufacturer: Maxim Integrated Products

Specifications of MAX8550AETI+

• Applications: Controller, DDR
• Voltage - Input: 2 ~ 28 V
• Number Of Outputs: 2
• Voltage - Output: 1.8V, 2.5V, 0.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Output Voltage: 0.7 V to 5.5 V, 1.8 V, 2.5 V
• Output Current: 1.5 A
• Input Voltage: 2 V to 28 V
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The inductor ripple current also affects transient-
response performance, especially at low V
ferentials. Low inductor values allow the inductor
current to slew faster, replenishing charge removed
from the output filter capacitors by a sudden load step.
The output sag is also a function of the maximum duty
factor, which can be calculated from the on-time and
minimum off-time:
Integrated DDR Power-Supply Solution for
Desktops, Notebooks, and Graphic Cards
Figure 8. Typical Applications Circuit
24
1.25V / ±1.5A
1.25V / 10mA
POK1
POK2
______________________________________________________________________________________
100kΩ
VTTR
VTT
R2
0.22μF
C10
20kΩ
R3
100kΩ
R5
41.2kΩ
10μF
Transient Response (Buck)
C4
60μF
R6
3.9nF
C2
C9
C6
1μF
R4
187kΩ
VTTI
VTT
VTTS
PGND2
VTTR
OVP/UVP
POK
SKIP
TON
GND
SS
REF
ILIM
FB
OUT
MAX8550A
REFIN
IN
PGND1
0.01μF
- V
SHDN
AV
STBY
C1
V
BST
TP0
V
DH
DL
DD
DD
LX
IN
OUT
dif-
D1
CMOSH-3
R1
10Ω
C7
0.22μF
where t
Electrical Characteristics) and K is from Table 1.
1μF
C3
V
SAG
ON
2 x 10μF
Q1
IRF7821
N-CHANNEL
30V, 9mΩ
N-CHANNEL
C5
4.7μF
30V,5mΩ
TOKO FDA1254-1R0M
C8
IRF7832
1.0μH, 21A,
OFF
=
Q2
OFF(MIN)
2
C
L
L1
OUT
×
C14
470μF
(OPTIONAL)
1.6mΩ
Δ
I
×
LOAD MAX
is the minimum off-time (see the
V
OUT
(
⎡
⎢
⎢
⎣
(
)
V
2
IN
⎡
⎢
⎣
V
-
25mΩ, LOW-ESR POS
C11, C12 (150μF, 4V,
SANYO 4TPE150M
OUT
V
CAPACITOR (D2E)
C11
150μF
OUT
V
IN
V
IN
5V
BIAS
SUPPLY
V
×
)
IN
×
(4.5V TO 28V)
K
C12
150μF
K
+
+
t
OFF MIN
t
OFF MIN
C13
1μF
(
2.5V / 12A
(
)
⎤
⎥
⎦
)
⎤
⎥
⎥
⎦