MAX8655ETN+ Maxim Integrated Products, MAX8655ETN+ Datasheet - Page 13

• Manufacturer Part Number: MAX8655ETN+
• Description: IC STEP-DN REG 25A 56-TQFN-EP
• Manufacturer: Maxim Integrated Products
• Type: Step-Down (Buck)r

Specifications of MAX8655ETN+

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 0.7 ~ 5.5 V
• Current - Output: 25A
• Frequency - Switching: 200kHz ~ 1MHz
• Voltage - Input: 4.5 ~ 25 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 56-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The MAX8655 has a reference input (REFIN). When an
external reference up to 1.5V is connected to REFIN,
the feedback regulation voltage is equal to the voltage
applied to REFIN.
Connect REFIN to AVL to use the internal 0.7V reference.
The MAX8655 provides output overvoltage protection
(OVP). The OVP threshold is set independent of the
output regulation voltage with a resistor voltage-divider.
When the voltage at OVP exceeds the OVP threshold,
the regulator stops switching and latches on the low-
side power MOSFET. Cycle EN or the power applied to
AVL to clear the latch.
Figure 3. Single-Phase, 600kHz Switching, 10.8V to 13.2V Input, and 1.2V/20A Output
FSYNC INPUT
SYNC OUTPUT
FOR INTERNAL
OSCILLATOR
OPERATION ONLY
11.8V TO 13.2V
POWER-OK OUTPUT
INPUT
CERAMIC
3 x 10μF
C1–C3
41.2kΩ
VL
0.22μF
R8
C15
D1
______________________________________________________________________________________
100kΩ
Internal MOSFET, Step-Down Regulator
R13
AVL
Overvoltage Protection
POK
FSYNC
MODE
SYNCO
BST
GND
N.C.
LXB
PVIN
PVIN
PVIN
PVIN
PVIN
PVIN
Highly Integrated, 25A, Wide-Input,
R10
51.1kΩ
0.022μF
AVL
C13
80.6kΩ
R12
REFIN
R7
40.2kΩ
C12
470pF
MAX8655
R5
4.02kΩ
2.87kΩ
POK is an open-drain output on the MAX8655 that mon-
itors the output voltage. When the output is above 92%
of its nominal regulation voltage, POK is high imped-
ance. When the output drops below 89% of its nominal
regulation voltage, POK is internally pulled low. POK is
also internally pulled low when the MAX8655 is shut
down or in a fault condition.
Thermal-overload protection limits total power dissipa-
tion in the MAX8655. When the junction temperature
exceeds +160°C, an internal thermal sensor shuts
down the device, allowing the IC to cool. The thermal
sensor turns the IC on again after the junction tempera-
ture cools by 15°C, resulting in a pulsed output during
continuous thermal-overload conditions.
56.2kΩ
R3
R9
100pF
C10
0.47μF
357Ω
R2
C8
VLGND
PGND
Thermal-Overload Protection
GND
GND
AVL
EN
VL
LX
LX
LX
LX
LX
LX
IN
Power-Good Signal (POK)
C14
1μF
C18
2.2μF
C16
0.22μF
PVIN
R1
681Ω
0.56μH
1.8mΩ
L1
0.47μF
C9
4 x 100μF
CERAMIC
ENABLE
C6–C20
INPUT
OUTPUT 1.2V
UP TO 20A
OFF
ON
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