A8650 Datasheet, PDF (1/31 Pages) Allegro MicroSystems – Low Input Voltage, Adjustable Frequency 2 A Synchronous Buck Regulator with EN/SYNC and Power OK

A8650
Low Input Voltage, Adjustable Frequency
2 A Synchronous Buck Regulator with EN/SYNC and Power OK
Features and Benefits
• Automotive AEC-Q100 qualified
• Operating voltage range: 2.5 to 5.5 V
• UVLO stop threshold: 2.25 V (max)
• Adjustable switching frequency (f_OSC): 0.25 to 2.45 MHz
• Synchronizes to external clock: 1.2× to 1.5× f_OSC (typ)
• Internal 70 mΩ high-side switching MOSFET
• Internal 55 mΩ low-side switching MOSFET
• Capable of at least 2.0 A steady-state output current
• Sleep mode supply current less than 3 μA
• Adjustable output voltage as low as 0.8 V with ±1%
accuracy from –40°C to 125°C
• Soft start time externally set via the SS pin
• Pre-biased startup capable
• Externally adjustable compensation
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Packages:
10-pin MSOP with exposed
thermal pad (suffix LY)
10-pin DFN with exposed
thermal pad (suffix EJ)
Description
The A8650 is an adjustable frequency, high output current,
PWM regulator that integrates a high-side, P-channel MOSFET
and a low-side, N-channel MOSFET. The A8650 incorporates
current-mode control to provide simple compensation, excellent
loop stability, and fast transient response. The A8650 utilizes
external compensation to accommodate a wide range of power
components to optimize transient response without sacrificing
stability. The A8650 regulates input voltages from 2.5 to 5.5 V,
down to output voltages as low as 0.8 V, and is able to supply
at least 2.0 A of load current.
A8650 features include an externally adjustable switching
frequency, an externally set soft start time to minimize inrush
currents, an EN/SYNC input to either enable V_OUT and/or
synchronize the PWM switching frequency, and a Power OK
(POK) output to indicate when V_OUT is within regulation. The
sleep mode current of the A8650 control circuitry is less than
3 μA. Protection features include V_IN undervoltage lockout
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Applications:
• GPS/Infotainment
• Automobile Audio
Not to scale
Typical Application Diagram
• Home Audio
• Network and Telecom
V_IN
CIN1
3.3 µF
1206
CIN2
0.1 µF
0805
CIN3
10 nF
0603
10 _VIN
SW ¹
9
2
A8650
GND
PGND
FB ⁷
EN/SYNC
C_SS
10 nF
R_FSET
10.7 kΩ
C_P
22 pF
3
8
5
6
R_Z
6.65 kΩ
C_Z
1.5 nF
EN/SYNC
SS
FSET
COMP
POK ⁴
L_O
1.0 µH
RFB1
9.09 kΩ
CO1
10 µF
1206
CO2
10 µF
1206
CO3
0.1 µF
0805
VOUT
CO4
10 nF
0603
RFB2
7.15 kΩ
3.3V
RPU
10 kΩ
POK
Typical application schematic, configured for V_IN = 5 V , V_OUT = 1.8 V, I_OUT = 2.0 A at 2 MHz
A8650-DS, Rev. 8