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Copyright © 2013 Active-Semi, Inc.
FEATURES
• 40V Input Voltage Surge
• 36V Steady State Operation
• Up to 3.5A output current
• Output Voltage up to 12V
• 125kHz Switching Frequency Eases EMI Design
• 91% Efficiency (Vout=5V@2.4A at Vin=12V)
• Stable with Low-ESR Ceramic Capacitors to
Allow Low-Profile Designs
• Integrated Over Voltage Protection
• Excellent EMI Performance
• Patented ActiveCC Sensorless Constant Current
Control Improves Efficiency and Lowers Cost.
• Resistor Programmable
− Current Limit from 1.5A to 4.0A
− Patented Cable Compensation from 0 to
0.25
• ±7.5% CC Accuracy
− Compensation of Input /Output Voltage Change
− Temperature Compensation
− Independent of inductance and Inductor DCR
• 2% Feedback Voltage Accuracy
• Advanced Feature Set
− Integrated Soft Start
− Thermal Shutdown
− Secondary Cycle-by-Cycle Current Limit
− Protection Against Shorted ISET Pin
• SOP-8EP Package
APPLICATIONS
• Car Charger/ Adaptor
• Rechargeable Portable Devices
• General-Purpose CV/CC Power Supply
GENERAL DESCRIPTION
ACT4533A/B is a wide input voltage, high efficiency
ActiveCC step-down DC/DC converter that operates
in either CV (Constant Output Voltage) mode or CC
(Constant Output Current) mode. ACT4533A/B
provides up to 3.5A output current at 125kHz
switching frequency.
ActiveCC is a patented control scheme to achieve
high-accuracy sensorless constant current control.
ActiveCC eliminates the expensive, high accuracy
current sense resistor, making it ideal for CLA
applications.
ACT4533A/B integrates adaptive gate drive to
achieve excellent EMI performance passing
EN55022 Class B EMC standard without adding
additional EMI components while maintaining high
conversion efficiency.
Protection features include cycle-by-cycle current
limit, thermal shutdown, and frequency foldback at
short circuit. The devices are available in a SOP-
8EP package and require very few external devices
for operation.
The only difference between ACT4533A and
ACT4533B is that Pin 7 provides OVP for
ACT4533A and EN/OVP for ACT4533B.
ACT4533A/B
Wide-Input Sensorless CC/CV Step-Down DC/DC Converter
Output Voltage (V)
Output Current (A)
1.4 1.6 1.8 2.0 2.2 2.4 2.6 2.8 3.0
ACT4533A/B-001
6.0
5.0
4.0
3.0
2.0
1.0
0.0
CC/CV Curve
Rev 0, 14-Aug-13
VIN = 18V
VIN = 24V
VIN = 12V
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
ORDERING INFORMATION
PART NUMBER OPERATION AMBIENT
TEMPERATURE RANGE OVP/EN
PIN PINS PACKING
ACT4533BYH-T -40°C to 85°C OVP/EN 8 TAPE & REEL
ACT4533AYH-T -40°C to 85°C OVP 8 TAPE & REEL
PACKAGE
SOP-8EP
SOP-8EP
PIN CONFIGURATION
PIN DESCRIPTIONS
PIN NAME DESCRIPTION
1 HSB
High Side Bias Pin. This provides power to the internal high-side MOSFET gate driver.
Connect a 22nF capacitor from HSB pin to SW pin.
2 IN
Power Supply Input. Bypass this pin with a 10µF ceramic capacitor to GND, placed as
close to the IC as possible.
3 SW Power Switching Output to External Inductor.
4 GND
Ground. Connect this pin to a large PCB copper area for best heat dissipation. Return
FB, COMP, and ISET to this GND, and connect this GND to power GND at a single
point for best noise immunity.
5 FB
Feedback Input. The voltage at this pin is regulated to 0.808V. Connect to the resistor
divider between output and GND to set the output voltage.
6 COMP Error Amplifier Output. This pin is used to compensate the converter.
7 EN/OVP
ACT4533A:OVP input. If the voltage at this pin exceeds 0.8V, the IC shuts down high-
side switch. There is a 4µA pull-up current at this pin.
ACT4533B: EN/OVP input. If the voltage at this pin is below 0.65V, the IC remains
shut-off; if the Voltage at this pin exceeds 2.26V, the IC shuts down high side switch.
There is a 4µA pull-up current at this pin.
8 ISET
Output Current Setting Pin. Connect a resistor from ISET to GND to program the
output current.
Exposed Pad
Heat Dissipation Pad. Connect this exposed pad to large ground copper area with
copper and vias.
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
ABSOLUTE MAXIMUM RATINGSc
PARAMETER VALUE UNIT
IN to GND -0.3 to 40 V
SW to GND -1 to VIN + 1 V
HSB to GND VSW - 0.3 to VSW + 7 V
FB, ISET, COMP to GND -0.3 to + 6 V
Junction to Ambient Thermal Resistance 46 °C/W
Operating Junction Temperature -40 to 150 °C
Storage Junction Temperature -55 to 150 °C
Lead Temperature (Soldering 10 sec.) 300 °C
c: Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods may
affect device reliability.
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
Input Voltage 10 38 V
Input Voltage Surge 40 V
VIN UVLO Turn-On Voltage Input Voltage Rising 9.0 9.4 9.7 V
VIN UVLO Hysteresis Input Voltage Falling 1.1 V
Standby Supply Current VFB = 1V 0.9 1.4 mA
Feedback Voltage 792 808 824 mV
Internal Soft-Start Time 400 µs
Error Amplifier Transconductance VFB = VCOMP = 0.808V,
ICOMP = ± 10µA 650 µA/V
Error Amplifier DC Gain 4000 V/V
Switching Frequency VFB = 0.808V 125 kHz
Foldback Switching Frequency VFB = 0V 18 kHz
Maximum Duty Cycle 86 %
Minimum On-Time 290 ns
COMP to Current Limit Transconductance VCOMP = 1.2V 5.1 A/V
Secondary Cycle-by-Cycle Current Limit Duty = 0.5 6.8 A
Slope Compensation Duty = DMAX 3.2 A
ISET Voltage 1.0 V
ISET to IOUT DC Room Temp Current Gain IOUT / ISET, RISET = 7.87k 20000 A/A
CC Controller DC Accuracy RISET = 7.87k, VOUT = 4.0V 2650 mA
OVP Pin Voltage (ACT4533A) OVP Pin Voltage Rising 0.8 V
OVP Pin Voltage (ACT4533A) OVP Pin Voltage Falling 0.57 V
OVP Pin Voltage (ACT4533B) OVP Pin Voltage Rising 2.26 V
OVP Pin Voltage (ACT4533B) OVP Pin Voltage Falling 1.76 V
EN Pin Voltage (ACT4533B) EN Pin Voltage Rising 0.65 V
EN Pin Voltage (ACT4533B) EN Pin Voltage Falling 0.59 V
High-Side Switch ON-Resistance 85 m
Thermal Shutdown Temperature Temperature Rising 155 °C
Thermal Shutdown Temperature Hysteresis Temperature Falling 25 °C
ELECTRICAL CHARACTERISTICS
(VIN = 12V, TA = 25°C, unless otherwise specified.)
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
FUNCTIONAL BLOCK DIAGRAM FOR ACT4533A
FUNCTIONAL DESCRIPTION
CV/CC Loop Regulation
As seen in Functional Block Diagram, the
ACT4533A/B is a peak current mode pulse width
modulation (PWM) converter with CC and CV
control. The converter operates as follows:
A switching cycle starts when the rising edge of the
Oscillator clock output causes the High-Side Power
Switch to turn on and the Low-Side Power Switch to
turn off. With the SW side of the inductor now
connected to IN, the inductor current ramps up to
store energy in the magnetic field. The inductor
current level is measured by the Current Sense
Amplifier and added to the Oscillator ramp signal. If
the resulting summation is higher than the COMP
voltage, the output of the PWM Comparator goes
high. When this happens or when Oscillator clock
output goes low, the High-Side Power Switch turns
off.
At this point, the SW side of the inductor swings to
a diode voltage below ground, causing the inductor
current to decrease and magnetic energy to be
transferred to output. This state continues until the
cycle starts again. The High-Side Power Switch is
FUNCTIONAL BLOCK DIAGRAM FOR ACT4533B
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
FUNCTIONAL DESCRIPTION
driven by logic using HSB as the positive rail. This
pin is charged to VSW + 5V when the Low-Side
Power Switch turns on. The COMP voltage is the
integration of the error between FB input and the
internal 0.808V reference. If FB is lower than the
reference voltage, COMP tends to go higher to
increase current to the output. Output current will
increase until it reaches the CC limit set by the ISET
resistor. At this point, the device will transition from
regulating output voltage to regulating output
current, and the output voltage will drop with
increasing load.
The Oscillator normally switches at 125kHz.
However, if FB voltage is less than 0.6V, then the
switching frequency decreases until it reaches a
typical value of 18kHz at VFB = 0.15V.
Over Voltage Protection (ACT4533A)
The ACT4533A has an OVP pin. If the voltage at
this pin exceeds 0.8V, the IC shuts down high-side
switch. There is a 4µA pull-up current at this pin.
EN/OVP Pin (ACT4533B)
The ACT4533B has an enable input and OVP input
for turning the IC on and off.
If the voltage at this pin rises above 0.65V, the IC is
enabled. The EN contains a 60mV hysteresis and
4µA pull-up current source.
If the voltage at this pin is between 0.65V and
2.26V, the IC operates normally; if the voltage at
this pin exceeds 2.26V, the IC shuts down high-side
switch. The OVP contains a 500mV hysteresis and
4µA pull-up current source.
Thermal Shutdown
The ACT4533A/B disables switching when its
junction temperature exceeds 155°C and resumes
when the temperature has dropped by 25°C.
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
APPLICATIONS INFORMATION
Output Voltage Setting
Figure 1:
Output Voltage Setting
Figure 1 shows the connections for setting the
output voltage. Select the proper ratio of the two
feedback resistors RFB1 and RFB2 based on the
output voltage. Adding a capacitor in parallel with
RFB1 helps the system stability. Typically, use RFB2
10k and determine RFB1 from the following
equation:
CC Current Setting
ACT4533A/B constant current value is set by a
resistor connected between the ISET pin and GND.
The CC output current is linearly proportional to the
current flowing out of the ISET pin. The voltage at
ISET is roughly 1.1V and the current gain from
ISET to output is roughly 21000 (21mA/1µA). To
determine the proper resistor for a desired current,
please refer to Figure 2 below.
Figure 2:
Curve for Programming Output CC Current
CC Current Line Compensation
When operating at constant current mode, the
current limit increase slightly with input voltage. For
wide input voltage applications, a resistor RC may
be added to compensate line change and keep
output high CC accuracy, as shown in Figure 3.
Figure 3:
Iutput Line Compensation
Inductor Selection
The inductor maintains a continuous current to the
output load. This inductor current has a ripple that is
dependent on the inductance value:
Higher inductance reduces the peak-to-peak ripple
current. The trade off for high inductance value is
the increase in inductor core size and series
resistance, and the reduction in current handling
capability. In general, select an inductance value L
based on ripple current requirement:
where VIN is the input voltage, VOUT is the output
voltage, fSW is the switching frequency, ILOADMAX is
the maximum load current, and KRIPPLE is the ripple
factor. Typically, choose KRIPPLE = 30% to
correspond to the peak-to-peak ripple current being
30% of the maximum load current.
With a selected inductor value the peak-to-peak
inductor current is estimated as:
The peak inductor current is estimated as:
The selected inductor should not saturate at ILPK.
The maximum output current is calculated as:
(3)
(
)
SWIN
OUTINOUT
PKLPK fVL
VVV
I××
×
=
_
_
PKLPK
LOADMAXLPK _
I
2
1
II += (4)
Output Current vs. RISET
ACT4533A/B-002
Output Current (mA)
3500
3000
2500
2000
1500
1000
500
4500
4000
RISET (k)
2 6 10 14 18 22 26
(2)
(
)
RIPPLELOADMAXSWIN
OUTINOUT
KIfV
VVV
L
_
×
=
⎟
⎠
⎞
⎜
⎝
⎛−= 1
V808.0
V
RR OUT
2FB1FB (1)
VIN = 24V, VOUT = 4V
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
(6)
ESRRIPPLEOUTMAXRIPPLE RKIV
=
OUT
2
SW
IN
LCf28
V
×
+
APPLICATIONS INFORMATION CONT’D
LLIM is the internal current limit, which is typically
4.5A, as shown in Electrical Characteristics Table.
External High Voltage Bias Diode
It is recommended that an external High Voltage
Bias diode be added when the system has a 5V
fixed input or the power supply generates a 5V
output. This helps improve the efficiency of the
regulator. The High Voltage Bias diode can be a
low cost one such as IN4148 or BAT54.
Figure 4:
External High Voltage Bias Diode
This diode is also recommended for high duty cycle
operation and high output voltage applications.
Input Capacitor
The input capacitor needs to be carefully selected
to maintain sufficiently low ripple at the supply input
of the converter. A low ESR capacitor is highly
recommended. Since large current flows in and out
of this capacitor during switching, its ESR also
affects efficiency.
The input capacitance needs to be higher than
10µF. The best choice is the ceramic type,
however, low ESR tantalum or electrolytic types
may also be used provided that the RMS ripple
current rating is higher than 50% of the output
current. The input capacitor should be placed close
to the IN and G pins of the IC, with the shortest
traces possible. In the case of tantalum or
electrolytic types, they can be further away if a
small parallel 0.1µF ceramic capacitor is placed
right next to the IC.
Output Capacitor
The output capacitor also needs to have low ESR to
keep low output voltage ripple. The output ripple
voltage is:
Where IOUTMAX is the maximum output current,
KRIPPLE is the ripple factor, RESR is the ESR of the
output capacitor, fSW is the switching frequency, L is
the inductor value, and COUT is the output
capacitance. In the case of ceramic output
capacitors, RESR is very small and does not
contribute to the ripple. Therefore, a lower
capacitance value can be used for ceramic type. In
the case of tantalum or electrolytic capacitors, the
ripple is dominated by RESR multiplied by the ripple
current. In that case, the output capacitor is chosen
to have sufficiently low ESR.
For ceramic output capacitor, typically choose a
capacitance of about 22µF. For tantalum or
electrolytic capacitors, choose a capacitor with less
than 50m ESR.
Rectifier Diode
Use a Schottky diode as the rectifier to conduct
current when the High-Side Power Switch is off.
The Schottky diode must have current rating higher
than the maximum output current and a reverse
voltage rating higher than the maximum input
voltage.
(5)
PKLPK
LIMOUTMAX I
2
1
II _
_
=
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
VOUT C
OUT R
COMP C
COMP C
COMP2c
2.5V 47F Ceramic CAP 5.6k 10nF None
3.3V 47F Ceramic CAP 8.2k 10nF None
5V 47F Ceramic CAP 15k 10nF None
2.5V 220F/10V/30m 15k 2.2nF 47pF
3.3V 220F/10V/30m 15k 2.2nF 47pF
5V 220F/10V/30m 15k 2.2nF 47pF
(15)
(Ω)
(16)
COMP
ESRCOUTOUT
2COMP R
RC
C=
OUTOUT
6
COMP CV1045.6C _
×= (F) (14)
(13)
(F)
COMP
5
COMP R
1083.2
C×
=
(12)
(Ω)
OUTOUT
7CV1012.5 ×=
V808.0GG10
fCV2
R
COMPEA
SWOUTOUT
COMP ×
=
π
(11)
COMP2COMP
3P CRπ2
1
f=
(10)
COMPCOMP
1Z CRπ2
1
f=
(9)
OUTOUT
OUT
2P CVπ2
I
f=
(8)
(7)
COMPVEA
OUT
VDC GA
I
V808.0
A=
STABILITY COMPENSATION
Figure 5:
Stability Compensation
c: CCOMP2 is needed only for high ESR output capacitor
The feedback loop of the IC is stabilized by the
components at the COMP pin, as shown in Figure
5. The DC loop gain of the system is determined by
the following equation:
The dominant pole P1 is due to CCOMP:
The second pole P2 is the output pole:
The first zero Z1 is due to RCOMP and CCOMP:
And finally, the third pole is due to RCOMP and
CCOMP2 (if CCOMP2 is used):
The following steps should be used to compensate
the IC:
STEP 1. Set the cross over frequency at 1/10 of the
switching frequency via RCOMP:
STEP 2. Set the zero fZ1 at 1/4 of the cross over
frequency. If RCOMP is less than 15k, the equation
for CCOMP is:
If RCOMP is limited to 15k, then the actual cross
over frequency is 6.58 / (VOUTCOUT). Therefore:
STEP 3. If the output capacitor’s ESR is high
enough to cause a zero at lower than 4 times the
cross over frequency, an additional compensation
capacitor CCOMP2 is required. The condition for using
CCOMP2 is:
And the proper value for CCOMP2 is:
Though CCOMP2 is unnecessary when the output
capacitor has sufficiently low ESR, a small value
CCOMP2 such as 100pF may improve stability against
PCB layout parasitic effects.
Table 1 shows some calculated results based on
the compensation method above.
Table 1:
Typical Compensation for Different Ou tput
Voltages and Output Capacitor s
c: CCOMP2 is needed for high ESR output capacitor.
CCOMP2 47pF is recommended.
CC Loop Stability
The constant-current control loop is internally
compensated over the 1500mA-3500mA output
range. No additional external compensation is
required to stabilize the CC current.
Output Cable Resistance Compensation
To compensate for resistive voltage drop across the
charger's output cable, the ACT4533A/B integrates
a simple, user-programmable cable voltage drop
compensation using the impedance at the FB pin.
Use the curve in Figure 6 to choose the proper
feedback resistance values for cable compensation.
RFB1 is the high side resistor of voltage divider.
COMPVEA
EA
1P CAπ2
G
f=
(
)
OUT
OUT
ESRCOUT V006.0,
C
1077.1
MinR
6
_
×
×
≥
c
ACT4533A/B
Rev 0, 14-Aug-13
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STABILITY COMPENSATION CONT’D
In the case of high RFB1 used, the frequency
compensation needs to be adjusted
correspondingly. As show in Figure 7, adding a
capacitor in paralleled with RFB1 or increasing the
compensation capacitance at COMP pin helps the
system stability.
Figure 6:
Cable Compensation at Various Resistor
Divider Values
Figure 7:
Frequency Compensatio n for High RFB1
PC Board Layout Guidance
When laying out the printed circuit board, the
following checklist should be used to ensure proper
operation of the IC.
1) Arrange the power components to reduce the
AC loop size consisting of CIN, IN pin, SW pin
and the schottky diode.
2) Place input decoupling ceramic capacitor CIN as
close to IN pin as possible. CIN is connected
power GND with vias or short and wide path.
3) Return FB, COMP and ISET to signal GND pin,
and connect the signal GND to power GND at a
single point for best noise immunity. Connect
exposed pad to power ground copper area with
copper and vias.
4) Use copper plane for power GND for best heat
dissipation and noise immunity.
5) Place feedback resistor close to FB pin.
6) Use short trace connecting HSB-CHSB-SW loop
Figure 8 shows an example of PCB layout.
Figure 9 gives one typical car charger application
schematic and associated BOM list.
Figure 8: PCB Layout
ACT4533A/B-003
400
300
250
200
150
100
50
0
350
450
Delta Output Voltage (mV)
Output Current (A)
0 0.3 0.6 0.9 1.2 1.5 1.8 2.4 2.1
RFB1 = 300k
RFB1 = 240k
RFB1 = 150k
R
FB1
= 200k
R
FB1
= 100k
R
FB1
= 51k
Delta Output Voltage vs. Output Current
ACT4533A/B
Rev 0, 14-Aug-13
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Figure 9:
Typical Application Circuit for 5V/2.4A Car Ch arger with OVP Circuit
Table 2:
BOM List for 5V/2.4A Car Charger
ITEM REFERENCE DESC RIPTION MANUFACTURER QTY
1 U1 IC, ACT4533AYH, SOP-8EP Active-Semi 1
2 C1 Capacitor, Electrolytic, 47µF/50V, 6.37mm Murata, TDK 1
3 C2 Capacitor, Ceramic, 10µF/50V, 1206, SMD Murata, TDK 1
4 C3 Capacitor, Ceramic, 2.2nF/6.3V, 0603, SMD Murata, TDK 1
5 C4 Capacitor, Ceramic, 22nF/50V, 1206, SMD Murata, TDK 1
6 C5 Capacitor, Ceramic, 1nF/10V, 0603, SMD Murata, TDK 1
7 C6 Capacitor, Ceramic, 10µF/10V, 0603, SMD Murata, TDK 1
8 C7 Capacitor, Electrolytic, 220uF/10V, 6.37mm Murata, TDK 1
9 L1 Inductor, 40µH, 5A, 20%, SMD Tyco Electronics 1
10 D1 Diode, Schottky, 40V/5A, SK54BL Diodes 1
11 R1 Chip Resistor, 7.87k, 0603, 1% Murata, TDK 1
12 R2 Chip Resistor, 51k, 0603, 1% Murata, TDK 1
13 R3 Chip Resistor, 15k, 0603, 5% Murata, TDK 1
14 R4 Chip Resistor, 9.76k, 0603, 1% Murata, TDK 1
15 R5 Chip Resistor, 100k, 0603, 1% Murata, TDK 1
16 R6 Chip Resistor, 15k, 0603, 1% Murata, TDK 1
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
Figure 10:
Typical Application Circuit for 5V/2.4A Car Charger with OVP and Short Circuit Protection
Table 3:
BOM List for 5V/2.4A Car Charger
ITEM REFERENCE DESC RIPTION MANUFACTURER QTY
1 U1 IC, ACT4533BYH, SOP-8EP Active-Semi 1
2 C1 Capacitor, Electrolytic, 47µF/50V, 6.37mm Murata, TDK 1
3 C2 Capacitor, Ceramic, 10µF/50V, 1206, SMD Murata, TDK 1
4 C3 Capacitor, Ceramic, 2.2nF/6.3V, 0603, SMD Murata, TDK 1
5 C4 Capacitor, Ceramic, 22nF/50V, 1206, SMD Murata, TDK 1
6 C5 Capacitor, Ceramic, 1nF/10V, 0603, SMD Murata, TDK 1
7 C6 Capacitor, Ceramic, 10µF/10V, 0603, SMD Murata, TDK 1
8 C7 Capacitor, Electrolytic, 220uF/10V, 6.37mm Murata, TDK 1
10 L1 Inductor, 40µH, 5A, 20%, SMD Tyco Electronics 1
11 D1 Diode, Schottky, 40V/5A, SK54BL Diodes 1
12 R1 Chip Resistor, 7.87k, 0603, 1% Murata, TDK 1
13 R2 Chip Resistor, 51k, 0603, 1% Murata, TDK 1
14 R3 Chip Resistor, 15k, 0603, 5% Murata, TDK 1
15 R4 Chip Resistor, 9.76k, 0603, 1% Murata, TDK 1
16 R5 Chip Resistor, 150k, 0603, 1% Murata, TDK 1
17 R6 Chip Resistor, 68k, 0603, 1% Murata, TDK 1
9 C8 Capacitor, Electrolytic, 2.2uF/50V, 6.37mm Murata, TDK 1
18 R7 Chip Resistor, 47k, 0603, 5% Murata, TDK 1
19 R8 Chip Resistor, 2.2k, 0603, 5% Murata, TDK 1
20 R9 Chip Resistor, 820, 0603, 5% Murata, TDK 1
ACT4533A/B
Rev 0, 14-Aug-13
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Copyright © 2013 Active-Semi, Inc.
TYPICAL PERFORMANCE CHARACTERISTICS
(Schematic as show in Figure 9, Ta = 25°C, unless otherwise specified)
ACT4533A/B-007
2780
2740
2700
2660
2620
2580
CC Current (mA)
Temperature (°C)
-20 10 40 70 100
130
CC Current vs. Temperature
ACT4533A/B-008
CC Current vs. Input Voltage
CC Current (mA)
2850
2800
2750
2700
2650
2660
Input Voltage (V)
10 15 20 25 30 35 40
ACT4533A/B-009
Maximum Peak Current vs. Duty Cycle
Maximum CC Current (A)
9.0
8.0
7.0
6.0
5.0
4.0
3.0
Duty Cycle
10 20 30 40 50 90 60 70 80
Input Voltage (V)
10 15 20 25 30 40
35
ACT4533A/B-005
Switching Frequency vs. Input Voltage
Switching Frequency (kHz)
145
140
135
130
125
120
115
110
ACT4533A/B-006
Switching Frequency vs. Feedback Voltage
Switching Frequency (kHz)
150
120
90
60
30
0
Feedback Voltage (mV)
0 100 200 300 400 500 600 700 800 900
ACT4533A/B-004
Efficiency (%)
Load Current (A)
0 0.4 0.8 1.2 1.6 3.6 2.8 3.2
2.0 2.4
100
85
80
75
70
65
60
95
90
Efficiency vs. Load current
VIN =12V
VIN =18V
VOUT = 5V
VIN =24V
VOUT = 5V
VIN = 12V
IISET = 2.65A
ACT4533A/B
Rev 0, 14-Aug-13
Innovative PowerTM - 14 - www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
Start up into CC mode SW vs. Output Voltage Ripples
Start up into CC mode
ACT4533A/B-013
ACT4533A/B-014
ACT4533A/B-015
VOUT = 5V
RLORD = 1.5
IISET = 2.65A
VIN = 12V
CH1: VOUT, 2V/div
CH2: IOUT, 1A/div
TIME: 400µs/div
CH1: VOUT, 2V/div
CH2: IOUT, 1A/div
TIME: 400µs/div
VIN = 12V
VOUT = 5V
IOUT = 2.4A
CH1
CH2
CH1: VOUT Ripple, 20mV/div
CH2: SW, 10V/div
TIME: 4µs/div
VOUT = 5V
RLORD = 1.5
IISET = 2.65A
VIN = 24V
CH1
CH2
CH1
CH2
Standby Current vs. Input Volta ge
(FB=1V)
ACT4533A/B-010
1160
1120
1080
1040
1000
960
Shutdown Current (µA)
Input Voltage (V)
8 12 16 20 24 28 32 40
36
ACT4533A/B-012
Reverse Leakage Current (VIN Floating)
Reverse Leakage Current (µA)
160
120
80
40
0
VOUT (V)
0 1 2 3 4 5
(Schematic as show in Figure 9, Ta = 25°C, unless otherwise specified)
ACT4533A/B-011
Feedback Voltage vs. Input Voltage
Standby Supply Current (mA)
0.818
0.815
0.812
0.809
0.806
0.803
0.800
Input Voltage (V)
8 12 16 20 24 28 32 36 40
ACT4533A/B
Rev 0, 14-Aug-13
Innovative PowerTM - 15 - www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
SW vs. Output Voltage Ripple
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
ACT4533A/B-016
ACT4533A/B-017
Start up with VIN
ACT4533A/B-018
Load transient (80mA-1A-80mA)
ACT4533A/B-019
Output Short test
ACT4533A/B-020
ACT4533A/B-021
VIN = 24V
VOUT = 5V
IOUT = 2.4A
CH1
CH2
CH1: VRIPPLE, 50mV/div
CH2: SW, 10V/div
TIME: 4µs/div
VIN = 12V
VOUT = 5V
IOUT = 2.4A
CH1
CH2
CH1: VIN, 5V/div
CH2: VOUT, 2V/div
TIME: 400µs//div
Start up with VIN
CH1
CH2
CH1: VIN, 10V/div
CH2: VOUT, 2V/div
TIME: 400µs//div
CH1
CH2
CH1: VOUT, 50mV/div
CH2: IOUT, 1A/div
TIME: 400µs//div
Load transient (1A-2.4A-1A)
CH1
CH2
CH1: VOUT, 100mV/div
CH2: IOUT, 1A/div
TIME: 400µs//div
VIN = 12V
VOUT = 5V
IISET = 2.65A
CH1
CH2
CH1: VOUT, 2V/div
CH2: IL, 1A/div
TIME: 100µs//div
VIN = 24V
VOUT = 5V
IOUT = 2.4A
VIN = 12V
VOUT = 5V
IISET = 2.65A
VIN = 24V
VOUT = 5V
IISET = 2.65A
VIN = 24V
VOUT = 5V
IISET = 2.65A
(Schematic as show in Figure 9, Ta = 25°C, unless otherwise specified)
ACT4533A/B
Rev 0, 14-Aug-13
Innovative PowerTM - 16 - www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
Output Short test
ACT4533A/B-022
VIN = 24V
VOUT = 5V
IISET = 2.65A
CH1
CH2
CH1: VOUT, 2V/div
CH2: IL, 1A/div
TIME: 100µs//div
Output Short Recovery
VIN = 24V
VOUT = 5V
IISET = 2.65A
CH1
CH2
CH1: VOUT, 2V/div
CH2: IL, 1A/div
TIME: 400µs//div
Output Short Recovery
VIN = 12V
VOUT = 5V
IISET = 2.65A
CH1
CH2
CH1: VOUT, 2V/div
CH2: IL, 1A/div
TIME: 400µs//div
CH1: VIN, 5V/div
CH2: VOUT, 2V/div
TIME: 10ms//div
OVP Test (Start up with FB=0)
CH1
CH2
VIN = 12V
VOUT = 5V
IISET = 2.65A
(Schematic as show in Figure 9, Ta = 25°C, unless otherwise specified)
CH1
CH2
CH1: VEN/OVP, 1V/div
CH2: VOUT, 2V/div
TIME: 20ms//div
EN/OVP Test
ACT4533A/B-023
ACT4533A/B-024
ACT4533A/B-025
ACT4533A/B-026
ACT4533A/B
Rev 0, 14-Aug-13
Innovative PowerTM - 17 - www.active-semi.com
Copyright © 2013 Active-Semi, Inc.
PACKAGE OUTLINE
SOP-8EP PACKAGE OUTLINE AND DIMENSIONS
SYMBOL DIMENSION IN
MILLIMETERS DIMENSION IN
INCHES
MIN MAX MIN MAX
A 1.350 1.700 0.053 0.067
A1 0.000 0.100 0.000 0.004
A2 1.350 1.550 0.053 0.061
b 0.330 0.510 0.013 0.020
c 0.170 0.250 0.007 0.010
D 4.700 5.100 0.185 0.200
D1 3.202 3.402 0.126 0.134
E 3.800 4.000 0.150 0.157
E1 5.800 6.200 0.228 0.244
E2 2.313 2.513 0.091 0.099
e 1.270 TYP 0.050 TYP
L 0.400 1.270 0.016 0.050
0° 8° 0° 8°
Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. Users should evaluate each
product to make sure that it is suitable for their applications. Active-Semi products are not intended or authorized for use
as critical components in life-support devices or systems. Active-Semi, Inc. does not assume any liability arising out of
the use of any product or circuit described in this datasheet, nor does it convey any patent license.
Active-Semi and its logo are trademarks of Active-Semi, Inc. For more information on this and other products, contact
sales@active-semi.com or visit http://www.active-semi.com.
is a registered trademark of Active-Semi.
Note:
1. Lead Coplanarity is 0.1mm max.
2. Dimension D does not include mold flash, protrusions or gate burrs. Mold flash, protrusions or gate burrs shall not exceed
0.15mm per end.
3. Dimension E does not include interlead flash or protrusion. Interlead flash or protrusion shall not exceed 0.25mm per side.
