ACTIVE-SEMI ACT4455

ACT4455
Rev 2, 21-Nov-12
36V/5A Step Down DC/DC Converter
FEATURES
APPLICATIONS
•
•
•
•
•
7.5V to 36V Input Voltage
40V Input Voltage Surge
Up to 5A Output Current
• Automotive Industry
• Dual-Output Car Charger
• LCD-TV
Up to 12V Output Voltage
GENERAL DESCRIPTION
Dual Outputs with Independent Over Current
Protection
•
•
•
•
•
•
•
7.5% Accurate Over Current Protection (OCP)
•
•
•
•
•
•
Auto Recovery into Full Load after Faults
ACT4455 is a wide input voltage step-down DC/DC
converter with high-side MOSFET integrated. It
provides up to 5A continuous output current at
200kHz switching frequency. The converter can be
configured as single output or dual outputs with
independent over current protection. The converter
achieves high efficiency and excellent load and line
regulation. The converter enters into hiccup and
sleeping mode and the converter power
consumption is nearly zero when output is
overloaded or shorted to ground. Other protection
features includes cycle-by-cycle current limit, under
voltage protection and thermal shutdown. The
device is available in SOP8-EP package.
Integrated 45mΩ High Side Power FET
90% Efficiency at Heavy Load
Internal 3ms Soft Startup
Low Standby Input Current
Sleeping Mode at OCP, OTP and SCP
Zero Input and Output Currents at Over Current
and Short Circuit Protection
Output Cord Voltage Drop Compensation
Stable with Low ESR Ceramic Output Capacitors
Internal Cycle-by-Cycle Current Control
Programmable Over Current Setting
SOP-8EP Package
Efficiency vs. Load current
Output current (V)
ACT4455-001
100
VIN = 12V
90
80
VIN = 24V
VIN = 32V
70
60
50
0
1000
2000
3000
4000
5000
Efficiency (%)
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-1-
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
ORDERING INFORMATION
PART NUMBER
OPERATION TEMPERATURE RANGE
ACT4455YH-T
-40°C to 85°C
PACKAGE
PINS
PACKING
SOP-8EP
8
TAPE & REEL
PIN CONFIGURATION
PIN DESCRIPTIONS
PIN
NAME
DESCRIPTION
1
CS1
The output current of VOUT1 is sensed by this pin. When the voltage on this pin reaches
116mV for 750µs, the IC shuts down for 2.5 seconds before initiating a restartup.
2
SW
Switch Output. Connect this pin to the switching end of the external inductor.
3
HSB
High Side Bias. This pin acts as the positive rail for the high-side switch’s gate driver.
Connect a 22nF-100nF capacitor between HSB and SW pins.
4
GND
Ground.
5
COMP
6
FB
Feedback Input. FB senses the output voltage to regulate that voltage. Drive FB with a
resistive voltage divider from the output voltage. The feedback threshold is 0.808V.
See Setting the Output Voltage.
7
IN
Input Supply. Bypass this pin to GND with a 10µF or greater low ESR capacitor.
8
CS2
Exposed Pad
Innovative PowerTM
Compensation Node. COMP is used to compensate the voltage regulation loop.
The output current of VOUT2 is sensed by this pin. When the voltage on this pin reaches
116mV for 750µs, the IC shuts down for 2.5 seconds and then restarts.
Exposed Pad. Connect this pad to thick copper plane via copper vias.
-2-
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
ABSOLUTE MAXIMUM RATINGSc
PARAMETER
VALUE
UNIT
-0.3 to 44
V
SW to GND
-0.3 to VIN + 0.3
V
HSB to GND
VSW - 0.3 to VSW + 7
V
-0.3 to + 6
V
50
°C/W
Operating Junction Temperature
-40 to 150
°C
Storage Junction Temperature
-55 to 150
°C
300
°C
IN to GND
FB, CS1, CS2, COMP to GND
Junction to Ambient Thermal Resistance
Lead Temperature (Soldering 10 sec.)
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.
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
ELECTRICAL CHARACTERISTICS
(VIN = 12V, TA = 25°C, unless otherwise specified.)
PARAMETER
SYMBOL
Feedback Voltage
VFB
Error Amplifier Voltage Gain
AEA
Error Amplifier Transconductance
GEA
Over Voltage Protection Threshold
VOVP
TEST CONDITIONS
7.5V ≤ VIN ≤ 40V
MIN
TYP
MAX
UNIT
798
808
818
mV
∆ICOMP = ± 10µA
4000
V/V
650
µA/V
41
V
Max E/A Source Current
ISRCMAX
VFB = 0.5V
120
µA
Max E/A Sink Current
ISINKMAX
VFB = 1.0V
120
µA
High-Side Switch ON-Resistance
RDS(ON)1
At 25°C
38
mΩ
Low-Side Switch ON-Resistance
RDS(ON)2
5
Ω
Maximum Duty Cycle
DMAX
80
%
Switching Frequency
FSW
Upper Switch Current Limit
ILIM
180
Duty Cycle = 65%
200
220
kHz
6.5
A
COMP to Current Limit
Transconductance
GCOMP
5
A/V
Minimum on Time
TON_MIN
250
ns
Input Under Voltage Lockout Threshold
VIN_Rise
VIN Rising
Input Under Voltage Lockout Hysteresis
VIN_Falling
VIN Falling
6.75
7
7.25
V
650
mV
3.0
ms
Internal Soft Startup Time
TSS
CS1 reference voltage
VCS1
113
116
119
mV
CS2 reference voltage
VCS2
113
116
119
mV
Frequency Foldback Threshold
Cord Compensation
VFB_Foldback
VIN = 12V, RFB1=200k, IOUT =
5A
Thermal Shutdown
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0.65
V
0.35
V
150
°C
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
FUNCTIONAL BLOCK DIAGRAM
FUNCTIONAL DESCRIPTION
FB is lower than the reference voltage, COMP
tends to go higher to increase current to the output.
Operation
As seen in Functional Block Diagram, the ACT4455
is a current mode controlled regulator. The EA
output voltage (COMP voltage) is proportional to
the peak inductor current.
Over Current and Short Circuit
Protection
CS pins are connected to the high side of current
sensing resistors to prevent output over current.
With independent CS1 and CS2 pins, two output
currents are detected. If the voltage at either CS
pins exceeds 116mV for more than 750µs. The
converter shuts down and goes into sleeping mode.
A new soft startup is triggered after 2.5s. If the fault
condition is un-cleared, the converter shuts down
again until over current condition is cleared. With
this long-waiting-time hiccup mode, the power
consumption at over loading or outputs short is
reduced to nearly zero.
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. 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 and the
inductor freewheels through the schottky diode
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 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 internal 0.808V reference. If
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Thermal Shutdown
The ACT4455 shuts down when its junction
temperature exceeds 150°C. The converter triggers
a soft-start when the temperature has dropped by
10°C. The soft-restart avoids output over voltage at
thermal hiccup.
-5-
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
APPLICATIONS INFORMATION
With a selected inductor value the peak-to-peak
inductor current is estimated as:
Output Voltage Setting
Figure 1:
ILPK _ PK =
Output Voltage Setting
VOUT × (VIN _VOUT )
L × VIN × fSW
(4)
The peak inductor current is estimated as:
I LPK = I LOADMAX +
1
I
2 LPK
_
(5)
PK
The selected inductor should not saturate at ILPK.
The maximum output current is calculated as:
1
IOUTMAX = I LIM _ I LPK PK
(6)
2
ILIM is the internal current limit, which is typically
6.5A, as shown in Electrical Characteristics Table.
_
Figure 1 shows the connections for setting
output voltage. Select the proper ratio of the
feedback resistors RFB1 and RFB2 based on
output voltage. Typically, use RFB2 ≈ 10kΩ
determine RFB1 from the following equation:
⎛ V OUT
⎞
R FB 1 = R FB 2 ⎜
−1⎟
0
.
808
V
⎝
⎠
the
two
the
and
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.
(1)
Over Current Protection Setting
The output over current threshold is calculated by:
IOCP1 = IOCP 2 = 116 mV / RSENSE
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.
(2)
It is recommended that 1% or 0.5% high-accuracy
current sensing resistor is selected to achieve highaccuracy over current protection. Two over current
protection thresholds can be different based on
different current sensing resistance.
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:
Output Capacitor
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:
VRIPPLE = IOUTMAX K RIPPLE RESR +
L=
× (V
)
VOUT
IN VOUT
VIN fSW ILOADMAX K RIPPLE
_
The output capacitor also needs to have low ESR to
keep low output voltage ripple. The output ripple
voltage is:
2
28 × fSW LC OUT
(7)
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
(3)
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.
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-6-
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
APPLICATIONS INFORMATION CONT’D
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 50mΩ 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.
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ACT4455
Rev 2, 21-Nov-12
STABILITY COMPENSATION
If RCOMP is limited to 15kΩ, then the actual cross
over frequency is 6.36 / (VOUTCOUT). Therefore:
Figure 2:
Stability Compensation
CCOMP = 6.67 ×10−6VOUTCOUT
c: CCOMP2 is needed only for high ESR output capacitor
⎛ 1.1 × 10 −6
⎞
RESRCOUT ≥ Min⎜⎜
,0.012 × VOUT ⎟⎟
C
OUT
⎝
⎠
The feedback loop of the IC is stabilized by the
components at the COMP pin, as shown in Figure
2. The DC loop gain of the system is determined by
the following equation:
0 . 808 V
AVEA G COMP
I OUT
G EA
2 π AVEA C COMP
(8)
The second pole P2 is the output pole:
fP 2
fP 3 =
(11)
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:
R COMP =
= 0 . 48 × 10 VOUT C OUT (Ω)
3 . 18 × 10
R COMP
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COUT
RCOMP
CCOMP CCOMP2c
2.5V
47μF SP CAP
5.6kΩ
5.6nF
3.3V
47μF SP CAP
7.5kΩ
4.7nF
None
5V
47μF SP CAP
11kΩ
3.3nF
None
None
2.5V
680μF/6.3V/30mΩ
15kΩ
3.3nF
220pF
3.3V
680μF/6.3V/30mΩ
15kΩ
3.3nF
220pF
5V
680μF/6.3V/30mΩ
15kΩ
4.7nF
220pF
Output Cable Resistance Compensation
To compensate for resistive voltage drop across the
charger's output cable, the ACT4455 integrates a
simple, user-programmable cable voltage drop
compensation using the impedance at the FB pin.
Use the curve in Figure 3 to choose the proper
feedback resistance values for cable compensation.
RFB1 is the high side resistor of voltage divider.
(13)
STEP 2. Set the zero fZ1 at 1/4 of the cross over
frequency. If RCOMP is less than 15kΩ, the equation
for CCOMP is:
C COMP =
VOUT
c: CCOMP2 is needed for high ESR output capacitor.
2 πVOUT C OUT f SW
10 G EA GCOMP × 0 .808 V
8
(17)
Typical Compensation for Different Output
Voltages and Output Capacitors
(12)
2πR COMP C COMP2
COUT RESRCOUT
RCOMP
Table 1:
And finally, the third pole is due to RCOMP and
CCOMP2 (if CCOMP2 is used):
1
CCOMP 2 =
Table 1 shows some calculated results based on
the compensation method above.
(10)
The first zero Z1 is due to RCOMP and CCOMP:
1
fZ 1 =
2 π R COMP C COMP1
(16)
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.
(9)
I OUT
=
2 π V OUT C OUT
(Ω)
And the proper value for CCOMP2 is:
The dominant pole P1 is due to CCOMP:
fP1 =
(15)
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:
c
AVDC =
(F)
−5
(F)
(14)
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
STABILITY COMPENSATION CONT’D
In the case of high RFB1 used, the frequency
compensation
needs
to
be
adjusted
correspondingly. As show in Figure 4, adding a
capacitor in paralled with RFB1 or increasing the
compensation capacitance at COMP pin helps the
system stability.
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.
Figure 3:
6) Use short trace connecting HSB-CHSB-SW loop
Cable Compensation at Various Resistor Divider
Values
7) SW pad is noisy node switching from VIN to
GND. It should be isolated away from the rest
of circuit for good EMI and low noise operation.
Delta Output Voltage vs. Output Current
Delta Output Voltage (V)
0.5
R
0.4
1
FB
=
0k
30
0k
27
0k
24
k
00
=2
v
ACT4455-002
0.6
=
B1
RF =
1
R FB
0.3
R FB
0.2
1
R FB1
R FB1
0.1
50k
=1
= 10
0k
RFB1 = 51k
0
0
1000
2000
3000
4000
5000
Output Current (mA)
Figure 4:
Frequency Compensation 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
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ACT4455
Rev 2, 21-Nov-12
Figure 5:
Typical Application Circuit for 5V/4.2A Dual-output Car Charger
Table 2:
BOM List for 5V/4.2A Dual-output Car Charger
ITEM REFERENCE
DESCRIPTION
MANUFACTURER
QTY
1
U1
IC ACT4455YH, SOP-8EP
Active-Semi
1
2
C1
Capacitor, Electrolytic, 150µF/50V, 8×8mm
Koshin
1
3
C2
Capacitor, Electrolytic, 680µF/10V, 8×11.5mm
Koshin
1
4
C3
Capacitor, Ceramic, 10µF/50V, 1206, SMD
Murata, TDK
1
5
C4
Capacitor, Ceramic, 4.7nF/25V, 0603, SMD
Murata, TDK
1
6
C5
Capacitor, Ceramic, 220pF/25V, 0603, SMD (Optional)
Murata, TDK
1
7
C6
Capacitor, Ceramic, 2.2nF/25V, 0603, SMD
Murata, TDK
1
8
C7
Capacitor, Ceramic, 1000pF/25V, 0603, SMD (Optional)
Murata, TDK
1
9
C8
Capacitor, Ceramic, 100pF/25V, 0603, SMD (Optional)
Murata, TDK
1
10
C9
Capacitor, Ceramic, 2200pF/25V, 0805, SMD
Murata, TDK
1
11
C10
Capacitor, Ceramic, 2.2µF/16V, 0603, SMD
Murata, TDK
1
12
L1
Inductor, 18µH, 5A, 20%, DIP
Electronic-Magnetics
1
13
D1
Diode, Schottky, 45V/10A, V10L45
Vishay
1
14
R1, R2
Chip Resistor, 50mΩ, 1206, 1%
Murata, TDK
2
15
R3
Chip Resistor, 9.7kΩ, 0603, 1%
Murata, TDK
1
16
R4
Chip Resistor, 51kΩ, 0603, 1%
Murata, TDK
1
17
R5
Chip Resistor, 15kΩ, 0603, 5%
Murata, TDK
1
18
R6
Chip Resistor, 5.1Ω, 1206, 5%
Murata, TDK
1
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
TYPICAL PERFORMANCE CHARACTERISTICS
(Circuit of Figure 7, RCS1 = RCS2 = 50mΩ, L = 18µH, CIN = 150µF, COUT = 680µF, TA = 25°C, unless otherwise specified.)
Efficiency vs. Load current
90
80
Switching Frequency (kHz)
VIN = 12V
VIN = 24V
VIN = 32V
70
60
50
ACT4455-004
Output current (V)
Switching Frequency vs. Input Voltage
250
ACT4455-002
100
200
150
100
50
0
0
1000
2000
3000
4000
5
5000
10
15
Efficiency (%)
30
40
35
PK Current limit (mA)
200
150
100
50
ACT4455-006
9
ACT4455-005
Switching Frequency (kHz)
25
Maximum Peak Current vs. Duty Cycle
Switching Frequency vs. Feedback Voltage
250
8.5
8
7.5
7
6.5
6
0
0
0.2
0.4
0.6
0.8
1
0.15
0.25
0.35
Feedback Voltage (mV)
0.45
0.55
0.65
0.75
0.85
Duty cycle
Input Current vs. Input Voltage at No Load
Standby Current vs. Input Voltage
900
12
Input Current (mA)
920
ACT4455-008
14
ACT4455-007
940
Standby Current (µA)
20
Input Voltage (V)
880
860
840
10
8
6
4
2
820
0
800
5
10
15
20
25
30
35
5
40
15
20
25
30
35
40
Input Voltage (V)
Input Voltage (V)
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(Circuit of Figure 7, RCS1 = RCS2 = 50mΩ, L = 18µH, CIN = 150µF, COUT = 680µF, TA = 25°C, unless otherwise specified.)
Input Current at Output Short Output
Vcs vs. Temperature
0.18
0.17
0.8
Vcs (V)
Input Current (mA)
1
ACT4455-010
ACT4455-009
1.2
0.6
0.16
VCS1
0.15
0.4
0.14
VCS2
0.2
0.13
0
5
10
15
20
25
30
35
-25
40
0
25
Input Voltage (V)
75
100
125
150
SW vs. Output Ripples
Start Up
ACT4455-012
ACT4455-011
VVINOUT
= 12V
= 5V
IR
= 1A
OUT
LORD = 1.5Ω
IISET = 2A
VIN = 12V
50
Temperature (°C)
VIN = 12V
IOUT = 0A
CH1
CH1
CH2
CH2
CH1: Ripper, 50mV/div
CH2: SW, 10V/div
TIME: 2µs/div
CH1: VOUT, 2V/div
CH2: VIN, 5V/div
TIME: 1ms/div
SW vs. Output Ripples
ACT4455-014
CH1
ACT4455-013
VIN = 12V
IOUT = 4.2A
Load Step Waveforms
VIN = 12V
IOUT1 = 0.08-2.1A
IOUT2 = 0A
CH1
CH2
CH2
CH1: Ripper, 50mV/div
CH2: SW, 10V/div
TIME: 2µs/div
Innovative PowerTM
CH1: VOUT Ripple, 200mV/div
CH2: IOUT, 2A/div
TIME: 400µs/div
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(Circuit of Figure 7, RCS1 = RCS2 = 50mΩ, L = 18µH, CIN = 150µF, COUT = 680µF, TA = 25°C, unless otherwise specified.)
Load Step Waveforms
Short Circuit
CH1
VIN = 12V
IOUT1 = 2.1A
IOUT2 = 0A
CH1
ACT4455-016
ACT4455-015
VIN = 12V
IOUT1 = 0-2.1A
IOUT2 = 2.1A
CH2
CH2
CH3
CH1: VOUT Ripper, 200mV/div
CH2: IOUT, 2A/div
TIME: 400µs/div
CH1: VOUT, 5V/div
CH2: IL, 2A/div
CH3: SW, 10V/div
TIME: 400µs/div
Short Circuit
Short Circuit Recovery
ACT4455-018
VIN = 12V
IOUT1 = 2.1A
IOUT2 = 2.1A
ACT4455-017
CH1
VIN = 12V
IOUT1 = 2.1A
IOUT2 = 0A
CH1
CH2
CH2
CH3
CH3
CH1: VOUT, 5V/div
CH2: IL, 2A/div
CH3: SW, 10V/div
TIME: 400µs/div
CH1: VOUT, 2V/div
CH2: IL, 2A/div
CH3: SW, 10V/div
TIME: 1ms/div
Hiccup Mode
Short Circuit Recovery
VIN = 12V
IOUT1 = 2.1A
IOUT2 = 2.1A
CH1
ACT4455-020
ACT4455-019
VIN = 12V
IOUT1 = 2.1A
IOUT2 = 2.1A
CH1
CH2
CH2
CH2
CH1: VOUT, 2V/div
CH2: IL, 2A/div
CH3: SW, 10V/div
TIME: 1ms/div
Innovative PowerTM
CH1: VOUT, 5V/div
CH2: SW, 5V/div
TIME: 1s/div
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
TYPICAL PERFORMANCE CHARACTERISTICS CONT’D
(Circuit of Figure 7, RCS1 = RCS2 = 50mΩ, L = 18µH, CIN = 150µF, COUT = 680µF, TA = 25°C, unless otherwise specified.)
Input Surge
VIN = 24V
VOUT = 5V
IISET = 2.1A
ACT4455-022
CH1
Input Surge
ACT4455-021
VIN = 8V-40V
IOUT1 = 2.1A
IOUT2 = 0 A
VIN = 8V-40V
IOUT1 = 2.1A
IOUT2 = 2.1A
CH1
CH2
CH2
CH1: VIN, 10V/div
CH2: VOUT Ripper, 200mV/div
TIME: 10ms/div
Innovative PowerTM
CH1: VIN, 10V/div
CH2: VOUT Ripper, 200mV/div
TIME: 10ms/div
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Copyright © 2012 Active-Semi, Inc.
ACT4455
Rev 2, 21-Nov-12
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
θ
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.
Innovative PowerTM
- 15 -
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Copyright © 2012 Active-Semi, Inc.