ON NCV47551DAJR2G 3.3 v to 20 v adjustable low noise ldo regulator with adjustable current limit and 3.3 v logic Datasheet

NCV47551
3.3 V to 20 V Adjustable
Low Noise LDO Regulator
with Adjustable Current
Limit and 3.3 V Logic
Compatible Enable Input
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The NCV47551 is a low noise low output current integrated low
dropout regulator designed for use in harsh automotive environments.
It includes wide operating temperature and input voltage ranges. The
device is offered with adjustable voltage versions available in 3%
output voltage accuracy. It has a high peak input voltage tolerance and
reverse input voltage protection. It also provides overcurrent
protection, overtemperature protection and enable for control of the
state of the output voltage. The integrated current sense feature
provides diagnosis and system protection functionality. The current
limit of the device is adjustable by resistor connected to CSO pin.
Voltage on CSO pin is proportional to output current.
Features
MARKING
DIAGRAM
8
SOIC−8
SUFFIX D
CASE 751
8
1
47551
A
L
Y
W
G
1
47551
ALYW
G
= Specific Device Code
= Assembly Location
= Wafer Lot
= Year
= Work Week
= Pb−Free Package
• Adjustable Voltage Version (from 3.3 V to 20 V) ± 3% Output
Voltage
ORDERING INFORMATION
• Enable Input (3.3 V Logic Compatible Thresholds)
• Adjustable Current Limit (from 100 mA to 20 mA) with 10%
See detailed ordering and shipping information in the package
dimensions section on page 11 of this data sheet.
Accuracy
• Protection Features:
Current Limitation
Thermal Shutdown
♦ Reverse Input Voltage
This is a Pb−Free Device
♦
♦
•
Typical Applications
•
•
•
•
Microphone Power Supply
Audio and Infotainment System
Navigation
Satellite Radio
Cin
1 mF
Vout
Vin
EN
NR
NCV47551
GND
Cb*
R1
ADJ
Cout
R2
CSO
CCSO
10 mF
RCSO
1 mF
Cnoise*
Cb*, Cnoise* − Optional for noise reduction.
Figure 1. Application Schematic
(See Application Section for more details)
© Semiconductor Components Industries, LLC, v2013
December, 2013 − Rev. 0
1
Publication Order Number:
NCV47551/D
NCV47551
Vin
Vout
NR
VOLTAGE
REFERENCE
VREF1
VREF2
PASS DEVICE
AND
CURRENT MIRROR
ENABLE
EN
SATURATION
PROTECTION
THERMAL
SHUTDOWN
ICSO = Iout
(Ratio 1:1)
SP
TSD
+
NOISE
REDUCTION
NR
NR
VREF2
2.55 V
−
CSO
SP
VREF1
1.265 V
+
GND
ADJ
−
TSD
Figure 2. Simplified Block Diagram
1
ADJ
8
Vout
GND
NC
EN
NR
CSO
Vin
SOIC−8
Figure 3. Pin Connections
(Top View)
PIN FUNCTION DESCRIPTION
Pin No.
SOIC−8
Pin Name
1
ADJ
Adjustable Voltage Setting Input. See Application Section for more details.
2
GND
Power Supply Ground.
3
EN
4
CSO
Description
Enable Input; low level disables the IC.
Current Sense Output, Current Limit setting and Output Current value information. See Application Section
for more details.
5
Vin
Positive Power Supply Input.
6
NR
Noise Reduction Input. Connect either external capacitor for decreasing noise or must be left unconnected.
7
NC
Not Connected.
8
Vout
Regulated Output Voltage.
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2
NCV47551
ABSOLUTE MAXIMUM RATINGS
Symbol
Min
Max
Unit
Input Voltage DC
Rating
Vin
−42
45
V
Enable Input Voltage
VEN
−42
45
V
Adjustable Input Voltage
VADJ
−0.3
10
V
CSO Voltage
VCSO
−0.3
7
V
Noise Reduction Input Voltage
VNR
−0.3
7
V
Output Voltage
Vout
−1
40
V
Junction Temperature
TJ
−40
150
°C
Storage Temperature
TSTG
−55
150
°C
Stresses exceeding those listed in the Maximum Ratings table may damage the device. If any of these limits are exceeded, device functionality
should not be assumed, damage may occur and reliability may be affected.
ESD CAPABILITY (Note 1)
Rating
Symbol
Min
Max
Unit
ESD Capability, Human Body Model
ESDHBM
−2
2
kV
ESD Capability, Machine Model
ESDMM
−200
200
V
Min
Max
Unit
1. This device series incorporates ESD protection and is tested by the following methods:
ESD Human Body Model tested per AEC−Q100−002 (JS−001−2010)
ESD Machine Model tested per AEC−Q100−003 (EIA/JESD22−A115)
LEAD SOLDERING TEMPERATURE AND MSL (Note 2)
Rating
Symbol
Moisture Sensitivity Level
MSL
Lead Temperature Soldering
Reflow (SMD Styles Only), Pb−Free Versions
TSLD
1
−
−
265 peak
°C
2. For more information, please refer to our Soldering and Mounting Techniques Reference Manual, SOLDERRM/D
THERMAL CHARACTERISTICS (Note 3)
Rating
Thermal Characteristics
Thermal Resistance, Junction−to−Air (Note 4)
Thermal Reference, Junction−to−Lead (Note 4)
Symbol
Value
RθJA
RψJL
133
76
Unit
°C/W
3. Refer to ELECTRICAL CHARACTERISTICS and APPLICATION INFORMATION for Safe Operating Area.
4. Values based on copper area of 645 mm2 (or 1 in2) of 1 oz copper thickness and FR4 PCB substrate.
RECOMMENDED OPERATING RANGES
Rating
Input Voltage (Note 5)
Nominal Output Voltage
Output Current Limit (Note 6)
Junction Temperature
Symbol
Min
Max
Unit
Vin
4.4
40
V
Vout_nom
3.3
20
V
ILIM
0.1
20
mA
TJ
−40
150
°C
Functional operation above the stresses listed in the Recommended Operating Ranges is not implied. Extended exposure to stresses beyond
the Recommended Operating Ranges limits may affect device reliability.
5. Minimum Vin = 4.4 V or (Vout_nom + 1 V), whichever is higher.
6. Corresponding RCSO is in range from 25.5 kW down to 127.5 W.
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NCV47551
ELECTRICAL CHARACTERISTICS Vin = 13.5 V, VEN = 3.3 V, RCSO = 0 W, CCSO = 1 mF, Cin = 1 mF, Cout = 10 mF, ESR = 1.5 W, Min
and Max values are valid for temperature range −40°C ≤ TJ ≤ +150°C unless noted otherwise and are guaranteed by test, design or
statistical correlation. Typical values are referenced to TJ = 25°C. Output Current Iout is the current out of pin including current through the
resistor divider R1 and R2. (Note 7)
Parameter
Test Conditions
Symbol
Min
Typ
Max
Unit
Vout
−3
−
+3
%
REGULATOR OUTPUT
Output Voltage (Accuracy %)
(Note 8)
Vin = Vin_min to 40 V
Iout = 0.1 mA to 20 mA
Line Regulation (Note 8)
Vin = Vin_min to (Vout_nom + 20 V)
Iout = 0.1 mA
Regline
−
0.1
1.0
%
Load Regulation
Iout = 0.1 mA to 20 mA
Vin = (Vout_nom + 8.5 V)
Regload
−
0.2
1.4
%
Dropout Voltage (Note 9)
Iout = 10 mA, Vout_nom = 5 V
VDO = Vin − Vout
VDO
−
210
500
mV
DISABLE AND QUIESCENT CURRENTS
Disable Current
VEN = 0 V
IDIS
−
0.075
10
mA
Quiescent Current, Iq = Iin − Iout
Iout = 0.1 mA, Vin = (Vout_nom + 8.5 V)
Iq
−
265
380
mA
Quiescent Current, Iq = Iin − Iout
Iout = 1 mA, Vin = (Vout_nom + 8.5 V)
Iq
−
1.45
3
mA
ILIM
20
−
50
mA
CURRENT LIMIT PROTECTION
Current Limit
Vout = 0.9 x Vout_nom, Vin = (Vout_nom + 8.5 V)
PSRR AND NOISE
Power Supply Ripple Rejection
(Note 10)
Iout = 1 mA, R1 = 82 kW, R2 = 27 kW
Cin = none, Cb = 10 nF, Cnoise = 10 nF
f = 100 Hz, 0.5 Vp−p
f = 1 kHz, 0.5 Vp−p
Output Noise Voltage (Note 10)
Iout = 1 mA, R1 = 82 kW, R2 = 27 kW, Cb = 10 nF
f = 10 Hz to 100 kHz, Cnoise = none
f = 10 Hz to 100 kHz, Cnoise = 10 nF
f = 20 Hz to 20 kHz, Cnoise = 10 nF
PSRR
Vn
dB
−
−
85
90
−
−
−
−
60
23
20
−
−
−
0.99
−
1.8
1.9
−
2.31
mVrms
ENABLE
Enable Input Threshold Voltage
Logic Low (OFF)
Logic High (ON)
Vout ≤ 0.1 V
Vout ≥ 0.9 x Vout_nom
Enable Input Current
VEN = 3.3 V
IEN
2
8
20
mA
Turn On Time
from ENABLE ON to
90% of Vout_nom
Iout = 1 mA
R1 = 82 kW, R2 = 27 kW
Cb = 10 nF, Cnoise = 10 nF
ton
−
2.8
−
ms
Vth(EN)
V
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product
performance may not be indicated by the Electrical Characteristics if operated under different conditions.
7. Performance guaranteed over the indicated operating temperature range by design and/or characterization tested at TA ≈ TJ. Low duty
cycle pulse techniques are used during testing to maintain the junction temperature as close to ambient as possible.
8. Vin_min = 4.4 V or (Vout_nom + 1 V), whichever is higher.
9. Measured when the output voltage Vout has dropped – 2% from the nominal value obtained at Vin = Vout_nom + 8.5 V.
10. Values based on design and/or characterization.
11. Not guaranteed in dropout.
12. ICSO current at no load includes also mirrored current of resistor divider (Idiv = Vout / (R1 + R2)).
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NCV47551
ELECTRICAL CHARACTERISTICS Vin = 13.5 V, VEN = 3.3 V, RCSO = 0 W, CCSO = 1 mF, Cin = 1 mF, Cout = 10 mF, ESR = 1.5 W, Min
and Max values are valid for temperature range −40°C ≤ TJ ≤ +150°C unless noted otherwise and are guaranteed by test, design or
statistical correlation. Typical values are referenced to TJ = 25°C. Output Current Iout is the current out of pin including current through the
resistor divider R1 and R2. (Note 7)
Parameter
Test Conditions
Symbol
Min
Typ
Max
2.346
(−8 %)
2.55
2.754
(+8 %)
Unit
OUTPUT CURRENT SENSE
CSO Voltage Level at Current
Limit
Vout = 0.9 x Vout_nom, (Vout_nom = 5 V)
RCSO = 220 W
CSO Transient Voltage Level
CCSO = 4.7 mF, RCSO = 220 W
Iout pulse from 0.1 mA to 20 mA, tr = 1 ms
VCSO
−
−
3.3
V
Output Current to CSO Current
Ratio (Note 11)
VCSO = 2 V
Iout = 0.1 mA to 20 mA, (Vout_nom = 5 V)
Iout/ICSO
−
(−10%)
(1/1)
−
(+10%)
−
CSO Current at no Load Current
(Note 12)
VCSO = 0 V
R1 = 82 kW, R2 = 27 kW, Cb = 10 nF
ICSO_off
−
47
60
mA
TSD
150
−
195
°C
VCSO_Ilim
V
THERMAL SHUTDOWN
Thermal Shutdown Temperature
(Note 10)
Iout = 1 mA
Product parametric performance is indicated in the Electrical Characteristics for the listed test conditions, unless otherwise noted. Product
performance may not be indicated by the Electrical Characteristics if operated under different conditions.
7. Performance guaranteed over the indicated operating temperature range by design and/or characterization tested at TA ≈ TJ. Low duty
cycle pulse techniques are used during testing to maintain the junction temperature as close to ambient as possible.
8. Vin_min = 4.4 V or (Vout_nom + 1 V), whichever is higher.
9. Measured when the output voltage Vout has dropped – 2% from the nominal value obtained at Vin = Vout_nom + 8.5 V.
10. Values based on design and/or characterization.
11. Not guaranteed in dropout.
12. ICSO current at no load includes also mirrored current of resistor divider (Idiv = Vout / (R1 + R2)).
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NCV47551
TYPICAL CHARACTERISTICS
450
Vin = 13.5 V
Iout = 100 mA
1.3
Iq, QUIESCENT CURRENT (mA)
VREF1, REFERENCE VOLTAGE (V)
1.31
1.29
1.28
1.27
1.26
1.25
1.24
1.23
1.22
−40 −20
0
20
40
60
80
350
300
250
200
150
100
TJ = 25°C
Iout = 100 mA
Vout_nom = 5 V
50
0
100 120 140 160
0
5
10
25
30
35
Figure 4. Reference Voltage vs. Temperature
Figure 5. Quiescent Current vs. Input Voltage
40
0
TJ = 25°C
Rout = 4.7 kW
Vout_nom = 5 V
Iin, INPUT CURRENT (mA)
−0.1
1
0.8
0.6
0.4
0.2
−0.2
−0.3
−0.4
−0.5
−0.6
−0.7
−0.8
−0.9
0
0
0.5 1
1.5
2
2.5
3
3.5
4
4.5
−1.0
−45
5.5 6
5
−40
−35
Vin, INPUT VOLTAGE (V)
Figure 6. Reference Voltage vs. Input Voltage
ILIM, OUTPUT CURRENT LIMIT (mA)
Vin = 13.5 V
Vout_nom = 5 V
450
400
TJ = 150°C
350
300
TJ = 25°C
250
200
150
TJ = −40°C
100
50
0
2
4
10 12
14 16
6
8
Iout, OUTPUT CURRENT (mA)
18
−30 −25 −20 −15 −10
Vin, INPUT VOLTAGE (V)
−5
0
Figure 7. Input Current vs. Input Voltage
(Reverse Input Voltage)
500
VDO, DROPOUT VOLTAGE (mV)
20
Vin, INPUT VOLTAGE (V)
TJ = 25°C
Iout = 100 mA
1.2
0
15
TJ, JUNCTION TEMPERATURE (°C)
1.4
VREF1, REFERENCE VOLTAGE (V)
400
42
Vout = 4.5 V
Vout_nom = 5 V
RCSO = 0 W
40
38
36
34
TJ = 25°C
32
30
TJ = 150°C
28
26
24
22
0
20
TJ = −40°C
Figure 8. Dropout vs. Output Current
5
10
15
20
25
30
35
Vin, INPUT VOLTAGE (V)
40
Figure 9. Output Current Limit vs. Input
Voltage
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45
NCV47551
TYPICAL CHARACTERISTICS
3.0
Vout = 3.3 V to 20 V
TJ = 25°C
20
15
10
5
0
0.1
10
1
Vout = 3.3 V to 20 V
TJ = 25°C
ILIM = 0.1 mA to 20 mA
2.5
VCSO, CSO VOLTAGE (V)
ILIM, OUTPUT CURRENT LIMIT (mA)
25
2.0
1.5
1.0
0.5
0
100
0
10
RCSO, (kW)
Figure 10. Output Current Limit vs. RCSO
40
9
8
7
6
5
4
3
2
1
0
1
30
25
20
15
10
5
0
0
5
2
3
4
Iout, OUTPUT CURRENT (mA)
5
10
15
20
Iout, OUTPUT CURRENT (mA)
25
Figure 13. Quiescent Current vs. Output Current
(High Load)
1
TJ = 25°C
Vin = Vout_nom + 8.5 V
Iout/ICSO, OUTPUT CURRENT TO
CSO CURRENT RATIO (−)
1.12
1.1
1.08
1.06
1.04
1.02
1
0.98
0.96
0.94
0.92
0.9
0.88
TJ = 25°C
Vin = Vout_nom + 8.5 V
35
Iq, QUIESCENT CURRENT (mA)
Iq, QUIESCENT CURRENT (mA)
TJ = 25°C
Vin = Vout_nom + 8.5 V
Figure 12. Quiescent Current vs. Output Current
(Low Load)
Iout/ICSO, OUTPUT CURRENT TO
CSO CURRENT RATIO (−)
110
Figure 11. Output Current (% of ILIM) vs. CSO
Voltage
10
0
20 30 40 50 60 70 80 90 100
Iout, OUTPUT CURRENT (% of ILIM)
0.95
0.9
0.85
0.8
0.75
0.7
TJ = 25°C
Vin = 4.5 V
Vout_nom = 5 V
0.65
0.6
0.1
1
10
Iout, OUTPUT CURRENT (mA)
100
0.1
Figure 14. Output Current to CSO Current
Ratio vs. Output Current
1
10
Iout, OUTPUT CURRENT (mA)
Figure 15. Output Current to CSO Current
Ratio vs. Output Current (In Dropout)
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100
NCV47551
1000
Unstable Region
Area above curves
10
1
Vout_nom = 20 V
Vout_nom = 5 V
0.1
0.01
0
Vout_nom = 3.3 V
Stable Region
Area below curves
2
4
6
10 12
14
16
8
Iout, OUTPUT CURRENT (mA)
18
20
3000
Noise 10 Hz − 100 kHz
Vn = 16.7 mVrms @ Cnoise = 100 nF
Vn = 26.1 mVrms @ Cnoise = 10 nF
2500
2000
Cnoise = 10 nF
1500
Cnoise = 100 nF
1000
0
10
100
1000
10000
FREQUENCY (Hz)
110
Cnoise = 10 nF
Cnoise = 100 nF
90
80
70
60
100000 1000000
Figure 17. Noise vs. Frequency
120
100
TJ = 25°C
Vin = 12 V
Cb = 10 nF
Vout_nom = 5 V
Iout = 20 mA
500
Figure 16. Output Capacitor Stability Region
vs. Output Current
PSRR (dB)
ESR (W)
100
TJ = 25°C
Vin = Vout_nom + 8.5 V
Cout = 1 mF − 100 mF
Cb = none
Vn, OUTPUT NOISE DENSITY (nV/Hz1/2)
TYPICAL CHARACTERISTICS
Cnoise = none
50 TJ = 25°C
Vin = 13.5 V (DC) + 0.5 VPP (AC)
40 Vout_nom = 5 V, Iout = 1 mA
Cb = 10 nF
30
10
100
1000
FREQUENCY (Hz)
10000
Figure 18. PSRR vs. Frequency
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100000
NCV47551
DEFINITIONS
General
reduces its internal bias and shuts off the output, this term is
called the disable current (IDIS).
All measurements are performed using short pulse low
duty cycle techniques to maintain junction temperature as
close as possible to ambient temperature.
Current Limit
Current Limit is value of output current by which output
voltage drops below 90% of its nominal value.
Output voltage
The output voltage parameter is defined for specific
temperature, input voltage and output current values or
specified over Line, Load and Temperature ranges.
PSRR
Power Supply Rejection Ratio is defined as ratio of output
voltage and input voltage ripple. It is measured in decibels
(dB).
Line Regulation
The change in output voltage for a change in input voltage
measured for specific output current over operating ambient
temperature range.
Line Transient Response
Typical output voltage overshoot and undershoot
response when the input voltage is excited with a given
slope.
Load Regulation
The change in output voltage for a change in output
current measured for specific input voltage over operating
ambient temperature range.
Load Transient Response
Typical output voltage overshoot and undershoot
response when the output current is excited with a given
slope between low-load and high-load conditions.
Dropout Voltage
The input to output differential at which the regulator
output no longer maintains regulation against further
reductions in input voltage. It is measured when the output
voltage Vout has dropped −2% from the nominal value
obtained at Vin = Vout_nom + 8.5 V. The junction temperature,
load current, and minimum input supply requirements affect
the dropout level.
Thermal Protection
Internal thermal shutdown circuitry is provided to protect
the integrated circuit in the event that the maximum junction
temperature is exceeded. When activated at typically 175°C,
the regulator turns off. This feature is provided to prevent
failures from accidental overheating.
Maximum Package Power Dissipation
Quiescent and Disable Currents
The power dissipation level is maximum allowed power
dissipation for particular package or power dissipation at
which the junction temperature reaches its maximum
operating value, whichever is lower.
Quiescent Current (Iq) is the difference between the input
current (measured through the LDO input pin) and the
output load current. If Enable pin is set to LOW the regulator
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NCV47551
APPLICATIONS INFORMATION
Circuit Description
Enable Input
The NCV47551 is an integrated low dropout regulator
that provides a regulated voltage at 20 mA to the output. It
is enabled with an input to the enable pin. The regulator
voltage is provided by a PNP pass transistor controlled by an
error amplifier with a bandgap reference, which gives it the
lowest possible dropout voltage. The output current
capability is 20 mA, and the base drive quiescent current is
controlled to prevent oversaturation when the input voltage
is low or when the output is overloaded. The integrated
current sense feature provides diagnosis and system
protection functionality. The current limit of the device is
adjustable by resistor connected to CSO pin. Voltage on
CSO pin is proportional to output current. The regulator is
protected by both current limit and thermal shutdown.
Thermal shutdown occurs above 150°C to protect the IC
during overloads and extreme ambient temperatures.
The enable pin is used to turn the regulator on or off. By
holding the pin down to a voltage less than 0.99 V, the output
of the regulator will be turned off. When the voltage on the
enable pin is greater than 2.31 V, the output of the regulator
will be enabled to power its output to the regulated output
voltage. The enable pin may be connected directly to the
input pin to give constant enable to the output regulator.
Setting the Output Voltage
The output voltage range can be set between 3.3 V and
20 V. This is accomplished with an external resistor divider
feeding back the voltage to the IC back to the error amplifier
by the voltage adjust pin ADJ. The internal reference voltage
is set to a temperature stable reference (VREF1) of 1.265 V.
The output voltage is calculated from the following formula.
Ignoring the bias current into the ADJ pin:
ǒ
V out_nom + V REF1 1 )
Regulator
The error amplifier compares the reference voltage to a
sample of the output voltage (Vout) and drives the base of a
PNP series pass transistor via a buffer. The reference is a
bandgap design to give it a temperature−stable output.
Saturation control of the PNP is a function of the load current
and input voltage. Oversaturation of the output power
device is prevented, and quiescent current in the ground pin
is minimized.
Ǔ
R1
R2
(eq. 1)
Use R2 < 50 kW to avoid significant voltage output errors
due to ADJ bias current.
Designers should consider the tolerance of R1 and R2
during the design phase.
Setting the Output Current Limit
The output current limit can be set between 0.1 mA and
20 mA by external resistor RCSO (see Figure 1). Capacitor
CCSO from range 1 mF to 4.7 mF in parallel with RCSO is
required for stability of current limit control circuitry (see
Figure 1).
Regulator Stability Considerations
The input capacitor (Cin) is necessary to stabilize the input
impedance to avoid voltage line influences. The output
capacitor (Cout) helps determine three main characteristics
of a linear regulator: startup delay, load transient response
and loop stability. The capacitor value and type should be
based on cost, availability, size and temperature constraints.
The aluminum electrolytic capacitor is the least expensive
solution, but, if the circuit operates at low temperatures
(−25°C to −40°C), both the value and ESR of the capacitor
will vary considerably. The capacitor manufacturer’s data
sheet usually provides this information. The value for the
output capacitor Cout, shown in Figure 1 should work for
most applications; see also Figure 14 for output stability at
various load and Output Capacitor ESR conditions. Stable
region of ESR in Figure 14 shows ESR values at which the
LDO output voltage does not have any permanent
oscillations at any dynamic changes of output load current.
Marginal ESR is the value at which the output voltage
waving is fully damped during four periods after the load
change and no oscillation is further observable.
ESR characteristics were measured with ceramic
capacitors and additional series resistors to emulate ESR.
Low duty cycle pulse load current technique has been used
to maintain junction temperature close to ambient
temperature.
V CSO + I out
I LIM +
2.55
R CSO
R CSO +
Where
RCSO
VCSO
ILIM
Iout
R CSO
2.55
I LIM
(eq. 2)
(eq. 3)
(eq. 4)
− current limit setting resistor
­ voltage at CSO pin proportional to Iout
− current limit value
− output current actual value
CSO pin provides information about output current actual
value. The CSO voltage is proportional to output current
according to Equation 2.
Once output current reaches its limit value (ILIM) set by
external resistor RCSO than voltage at CSO pin is typically
2.55 V. Calculations of ILIM or RCSO values can be done
using equations Equations 3 and 4, respectively.
Designers should consider the tolerance of RCSO during
the design phase.
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NCV47551
Thermal Considerations
Since TJ is not recommended to exceed 150°C, then the
NCV47551 in SO-8 soldered on 645 mm2, 1 oz copper area,
FR4 can dissipate up to 0.94 W when the ambient
temperature (TA) is 25°C. See Figure 19 for RthJA versus
PCB area. The power dissipated by the NCV47551 can be
calculated from the following equations:
As power in the NCV47551 increases, it might become
necessary to provide some thermal relief. The maximum
power dissipation supported by the device is dependent
upon board design and layout. Mounting pad configuration
on the PCB, the board material, and the ambient temperature
affect the rate of junction temperature rise for the part. When
the NCV47551 has good thermal conductivity through the
PCB, the junction temperature will be relatively low with
high power applications. The maximum dissipation the
NCV47551 can handle is given by:
RqJA, THERMAL RESISTANCE (°C/W)
P D(MAX) +
ƪTJ(MAX) * TAƫ
P D [ V inǒI q@I outǓ ) I outǒV in * V outǓ
(eq. 6)
or
V in(MAX) [
(eq. 5)
P D(MAX) ) ǒV out
I outǓ
I out ) I q
(eq. 7)
Hints
R qJA
Vin and GND printed circuit board traces should be as
wide as possible. When the impedance of these traces is
high, there is a chance to pick up noise or cause the regulator
to malfunction. Place external components, especially the
output capacitor, as close as possible to the NCV47551 and
make traces as short as possible.
240
220
200
180
1 oz, Single Layer
160
140
2 oz, Single Layer
120
100
0
100
200
300
400
500
600
700
COPPER HEAT SPREADER AREA (mm2)
Figure 19. Thermal Resistance vs. PCB Copper Area
ORDERING INFORMATION
Device
NCV47551DAJR2G
Output Voltage
Marking
Package
Shipping†
Adjustable
47551
SOIC−8
(Pb−Free)
2500 / Tape & Reel
†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
http://onsemi.com
11
NCV47551
PACKAGE DIMENSIONS
SOIC−8 NB
CASE 751−07
ISSUE AK
−X−
NOTES:
1. DIMENSIONING AND TOLERANCING PER
ANSI Y14.5M, 1982.
2. CONTROLLING DIMENSION: MILLIMETER.
3. DIMENSION A AND B DO NOT INCLUDE
MOLD PROTRUSION.
4. MAXIMUM MOLD PROTRUSION 0.15 (0.006)
PER SIDE.
5. DIMENSION D DOES NOT INCLUDE DAMBAR
PROTRUSION. ALLOWABLE DAMBAR
PROTRUSION SHALL BE 0.127 (0.005) TOTAL
IN EXCESS OF THE D DIMENSION AT
MAXIMUM MATERIAL CONDITION.
6. 751−01 THRU 751−06 ARE OBSOLETE. NEW
STANDARD IS 751−07.
A
8
5
S
B
0.25 (0.010)
M
Y
M
1
4
−Y−
K
G
C
N
DIM
A
B
C
D
G
H
J
K
M
N
S
X 45 _
SEATING
PLANE
−Z−
0.10 (0.004)
H
D
0.25 (0.010)
M
Z Y
S
X
S
M
J
SOLDERING FOOTPRINT*
MILLIMETERS
MIN
MAX
4.80
5.00
3.80
4.00
1.35
1.75
0.33
0.51
1.27 BSC
0.10
0.25
0.19
0.25
0.40
1.27
0_
8_
0.25
0.50
5.80
6.20
INCHES
MIN
MAX
0.189
0.197
0.150
0.157
0.053
0.069
0.013
0.020
0.050 BSC
0.004
0.010
0.007
0.010
0.016
0.050
0 _
8 _
0.010
0.020
0.228
0.244
1.52
0.060
7.0
0.275
4.0
0.155
0.6
0.024
1.270
0.050
SCALE 6:1
mm Ǔ
ǒinches
*For additional information on our Pb−Free strategy and soldering
details, please download the ON Semiconductor Soldering and
Mounting Techniques Reference Manual, SOLDERRM/D.
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC owns the rights to a number of patents, trademarks,
copyrights, trade secrets, and other intellectual property. A listing of SCILLC’s product/patent coverage may be accessed at www.onsemi.com/site/pdf/Patent−Marking.pdf. SCILLC
reserves the right to make changes without further notice to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any
particular purpose, nor does SCILLC assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without
limitation special, consequential or incidental damages. “Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications
and actual performance may vary over time. All operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC
does not convey any license under its patent rights nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for
surgical implant into the body, or other applications intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where
personal injury or death may occur. Should Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and
its officers, employees, subsidiaries, affiliates, and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly,
any claim of personal injury or death associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture
of the part. SCILLC is an Equal Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
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Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
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Phone: 81−3−5817−1050
http://onsemi.com
12
ON Semiconductor Website: www.onsemi.com
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For additional information, please contact your local
Sales Representative
NCV47551/D