MCU单片机写程序
MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
36V Synchronous Buck Converter With CC/CV
? GENERAL DESCRIPTION
MA5609 is a wide input voltage, high efficiency Active CC step-down DC/DC converter that
operates in either CV (Constant Output Voltage) mode or CC (Constant Output Current) mode.
MA5609 provides up to 3.5A output current at 160kHz switching frequency. Current mode control
provides fast transient response and cycle-by-cycle current limit.
An internal soft-start prevents inrush current at turn-on, This device, available in an
SOP8L-EP(Exposed pad) package, provides a very compact solution with minimal external
components.
? FEATURES   MCU单片机写程序
- Wide 8V to 36V Operating Input Range
- Integrated 75/45mΩ Power MOSFET Switches
- Output Adjustable from VFB(1.00V±2%) to 16V
- Up to 95% Efficiency
- Internal Soft-Start and Fixed 160KHz Frequency.
- Stable with Low ESR Polymer Al-E-Capacitors
- Cycle-by-Cycle Over Current Protection
- Input Under/Over Voltage Lockout
? APPLICATION CIRCUIT   
C1
4.7μF
35V 40k
10k
VOUT+
5V 3A
C6
0.1μF
IN
PGND
GND
SW
CS
FB
VIN=8~32V
30m
L1
33μH
C2
R1
R2
BS
C5
10nF
MA5609
R5
24
10μF
10V
PAD
C7
470μF
16V
C8
RSEN
VOUTCFB
3.3nF
GND
100μF
35V
VOUT=VFB × (1+R1/R2), VFB = 1.00V, R2 suggest 10k~40KΩ
ISEN = 3.3A (ISEN=VCS(0.1V) / RSEN(30mΩ))
2/9
MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
? PIN ASSIGNMENT
The package of MA5609 is SOP8L-EP(Exposed pad); the pin assignment is given by:
( Top View )
1
2
3
4
BS 8
SW
SOP8L-EP
MA5609
PGND
IN
GND
CS
GND
FB
(SW)
Name Description
BS Boot-Strap Pin. Supply high side gate driver. Decouple this pin to LX pin with 24ohm +
10nF ceramic cap.
IN Power Input pin. Bypass IN to GND with a suitably large capacitor to eliminate noise on
the input to the IC.
SW Power Switching Output. SW is the switching node that supplies power to the output.
Connect the output LC filter from SW to the output load.
PGND Power Ground.
PAD Power Switching Output. (Connect to SW PIN).
FB Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a
resistive voltage divider from the output voltage.
CS The Current Sense pin.
GND Ground.
? ORDER/MARKING INFORMATION    
Order Information Top Marking
Package Type
MA5609 Packing
A : Taping
XX X
Blank: Tube
ES: SOP8L-EP
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MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
? BLOCK DIAGRAM
Internal
Power
PWM Control
& Protect
FB Logic
M1
M2
CURRENT
SENSE
AMPLIFIER BS
SW
PGND
Input UVLO
7.0V
Softstart
Thermal
Protection
1V
1.1V
GND
CS
VDD
GND
0.1V
? A BSOLUTE MAXIMUM RATINGS (at TA=25°C)
Characteristics Symbol Rating Unit
Supply Voltage VIN –0.3 to +42 V
Switch Node Voltage VSW – 0.3 to VIN + 0.3 V
Boost Voltage VBS VSW – 0.3 to VSW + 6 V
All Other Pins –0.3 to +6 V
Lead Temperature 260 °C
Storage Temperature –65 to +150 °C
Junction Temperature TJ 150 °C
Output Voltage VOUT VFB to 6 V
Ambient Operating Temperature –40 to +85 °C
Thermal Resistance from Junction to case θJC 15 °C/W
Thermal Resistance from Junction to ambient θJA 40 °C/W
Note: θJA is measured with the PCB copper area of approximay 1 in2(Multi-layer). That need connect to exposed pad.
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MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
? ELECTRICAL CHARACTERISTICS
(VIN = 12V, TA = +25°C, unless otherwise noted.)
Characteristics Symbol Conditions Min Typ Max Units
Input Voltage Range 8 - 36 V
Quiescent Current ICCQ VFB = 1.05V - 1 1.5 mA
Feedback Voltage VFB 8V ≤ VIN ≤ 36V 0.98 1.00 1.02 V
Feedback Overvoltage Threshold OVP(FB) - 1.1X - VFB
Cable compensation current(Note) ICFB VCS=100mV - 4 - uA
High-Side Switch On Resistance (Note) RDS(ON)1 - 75 - mΩ
Low-Side Switch On Resistance (Note) RDS(ON)2 - 45 - mΩ
High-Side Switch Leakage Current VFB =1.05V, VSW = 0V - - 10 μA
Upper Switch Current Limit Minimum Duty Cycle 4.0 5.0 - A
Oscillation Frequency FOSC1 - 160 - KHz
Short Circuit Oscillation Frequency FOSC2 VFB =<0.4V - 80 - KHz
Short Circuit Retry time(Note) RTSCP VFB =< 0.5V - 1 - mS
Maximum Duty Cycle DMAX - 88 - %
Minimum On Time (Note) TON(min) - 220 - ns
Current Sense Voltage VcS 95 100 115 mV
VIN OVP Turn-Off Voltage Input Voltage Rising - 36 - V
VIN OVP Hysteresis Input Voltage Falling - 3 - V
Input Under Voltage Lockout Threshold UVLO VIN Rising 6.5 7.0 7.5 V
Input Under Voltage Lockout Threshold
Hysteresis UVLO-Hys - 800 - mV
Soft-Start Period - 2 - ms
Thermal Shutdown TSD - 155 - °C
Thermal Shutdown Hysterisis TSH - 30 - °C
Note: Guaranteed by design.
5/9
MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
? FUNCTION DESCRIPTIONS
The MA5609 is a synchronous rectified, current-mode, step-down regulator. It regulates
input voltages from 8V to 36V down to an output voltage as low as VFB, and supplies up to 3.5A of
load current.
The MA5609 uses current-mode control to regulate the output voltage. The output voltage is
measured at FB through a resistive voltage divider and amplified through the internal Tran
conductance error amplifier.
The converter uses internal N-Channel MOSFET switches to step-down the input voltage to
the regulated output voltage. Since the high side MOSFET requires a gate voltage greater than
the input voltage, a boost capacitor connected between SW and BS is needed to drive the high
side gate. The boost capacitor is charged from the internal 5V rail when SW is low.
When the MA5609 FB pin exceeds 10% of the nominal regulation voltage of VFB, the over
voltage comparator is tripped and the COMP pin is discharged to GND, forcing the high-side
switch off.
? APPLICATION INFORMATION
Setting the Output Voltage
The output voltage is set using a resistive voltage divider from the output voltage to FB pin.
The voltage divider divides the output voltage down to the feedback voltage by the ratio.
Thus the output voltage is:
VOUT= VFB ×
2
1 2
R
R ? R
For example, VFB =1.00V for a 5.0V output voltage, R2 is 10kΩ, and R1 is 40kΩ.
Inductor Selection
The inductor is required to supply constant current to the output load while being driven by
the switched input voltage. A larger value inductor will result in less ripple current that will result in
lower output ripple voltage. However, the larger value inductor will have a larger physical size,
higher series resistance, and/or lower saturation current. A good rule for determining the
inductance to use is to allow the peak-to-peak ripple current in the inductor to be approximay
30% of the maximum switch current limit.
VIN <28V <35V
Inductor 33uH 47uH
The choice of which style inductor to use mainly depends on the price vs. size requirements
and any EMI requirements.
6/9
MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
Output Short-Circuit protection
The MA5609 provides output short-circuit protection retry function. When VOUT is short
(VFB<0.5V), the auto restart function can be started that restart the regulator cycle by cycle.
(Retry time 1mS , Shutdown regulator time 20mS) .
Output Cable Resistance Compensation
To compensate for resistive voltage drop across the charger's output cable, the MA5609
integrates a simple, user-programmable cable voltage drop compensation using the impedance at
the FB pin. Use the curve in Figure 1 to choose the proper feedback resistance values for cable
compensation. R1 is the high side resistor of voltage divider. When ISEN is max setting current, it
can provide max cable compensation amount (0.17V at R1=40KΩ).
VOUT= VFB × ( 1+R1/R2 ) + R1 x ICFB(4uA)
VIN12V TO 5VOUT (RESE=39mΩ)
Figure1 Cable Compensation at Various Resistor Divider Values
Application circuit :
C1
4.7μF
35V 40kΩ
10kΩ
VOUT+
5V 3A
C6
0.1μF
IN
PGND
GND
SW
CS
FB
VIN=8~32V
30mΩ

MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
? TYPICAL CHARACTERISTICS
Power On: VIN = 12V, VOUT = 5V, ILOAD = 0A Power On: VIN = 12V, VOUT = 5V, ILOAD = 3.5A
Ch1=SW , Ch2=VOUT ,Ch3=VIN , Ch4=ISW Ch1=SW , Ch2=VOUT ,Ch3=VIN , Ch4=IOUT
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MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
Cable On: VIN = 12V, VOUT = 5V, ILOAD = 0A Cable On: VIN = 12V, VOUT = 5V, ILOAD = 3.5A
Ch1=SW , Ch2=VOUT ,Ch3=VIN , Ch4=ISW Ch1=SW , Ch2=VOUT ,Ch3=VIN , Ch4=ISW
12VIN Load Transient: ILOAD = 0.1A to 3A 24VIN Load Transient: ILOAD = 0.1A to 3A
Ch1=SW , Ch2= VRIPPLE ,Ch3=VIN , Ch4=ISW Ch1=SW , Ch2= VRIPPLE ,Ch3=VIN , Ch4=IOUT
12VIN Load Transient: ILOAD = 0A to 3A SCP Realse: VIN=12V, VOUT= 5V, ILOAD= 0A
Ch1=SW , Ch2=VRIPPLE ,Ch3=VIN , Ch4=IOUT Ch1=SW , Ch2=VOUT ,Ch3=VIN , Ch4=ISW
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MA5609
Major Power Technology Co., Ltd. Rev.1.3 Apr. 12 , 2017
? PACKAGE OUTLINES
DETAIL A

Symbol Dimensions in Millimeters Dimensions in Inches
Min. Nom. Max. Min. Nom. Max.

Mold flash shall not exceed 0.25mm per side
JEDEC outline: MS-012 BA