TI TPS7A3001DGNT

TPS7A30xx
www.ti.com
SBVS125 – AUGUST 2010
–36V, –200mA, Ultralow-Noise, Negative LINEAR REGULATOR
FEATURES
DESCRIPTION
•
•
The TPS7A30xx series of devices are negative,
high-voltage (–36V), ultralow-noise (15.1mVRMS, 72dB
PSRR) linear regulators capable of sourcing a
maximum load of 200mA.
1
23
•
•
•
•
•
•
•
•
•
Input Voltage Range: –3V to –36V
Noise:
– 14mVRMS (20Hz to 20kHz)
– 15.1mVRMS (10Hz to 100kHz)
Power-Supply Ripple Rejection:
– 72dB (120Hz)
– ≥ 55dB (10Hz to 700kHz)
Adjustable Output: –1.18V to –33V
Maximum Output Current: 200mA
Dropout Voltage: 216mV at 100mA
Stable with Ceramic Capacitors ≥ 2.2mF
CMOS Logic-Level-Compatible Enable Pin
Built-In, Fixed, Current-Limit and Thermal
Shutdown Protection
Available in High Thermal Performance
MSOP-8 PowerPAD™ Package
Operating Tempature Range: –40°C to +125°C
APPLICATIONS
•
•
•
•
•
•
•
•
Supply Rails for Op Amps, DACs, ADCs, and
Other High-Precision Analog Circuitry
Audio
Post DC/DC Converter Regulation and Ripple
Filtering
Test and Measurement
RX, TX, and PA Circuitry
Industrial Instrumention
Base Stations and Telecom Infrastrucure
–12V and –24V Industrial Buses
DGN PACKAGE
3mm ´ 5mm MSOP-8 PowerPAD
(TOP VIEW)
OUT
FB
NC
GND
1
2
3
4
8
7
6
5
IN
DNC
NR/SS
EN
These
linear
regulators
include
a
CMOS
logic-level-compatible
enable
pin
and
capacitor-programmable soft-start function that allows
for customized power-management schemes. Other
features available include built-in current limit and
thermal shutdown protection to safeguard the device
and system during fault conditions.
The TPS7A30xx family is designed using bipolar
technology, and is ideal for high-accuracy,
high-precision instrumentation applications where
clean voltage rails are critical to maximize system
performance. This design makes it an excellent
choice
to
power
operational
amplifiers,
analog-to-digital converters (ADCs), digital-to-analog
converters (DACs), and other high-performance
analog circuitry.
In addition, the TPS7A30xx family of linear regulators
is suitable for post dc/dc converter regulation. By
filtering out the output voltage ripple inherent to dc/dc
switching conversion, maximum system performance
is provided in sensitive instrumentation, test and
measurement, audio, and RF applications.
For applications where positive and negative
high-performance rails are required, consider TI’s
TPS7A49xx
family
of
positive
high-voltage,
ultralow-noise linear regulators.
Typical Application
+18V
IN
OUT
+15V
TPS7A49
-18V
EN
GND
IN
OUT
-15V
TPS7A30
EN
GND
EVM
Post DC/DC Converter Regulation for
High-Performace Analog Circuitry
1
2
3
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas
Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
PowerPAD is a trademark of Texas Instruments.
All other trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2010, Texas Instruments Incorporated
TPS7A30xx
SBVS125 – AUGUST 2010
www.ti.com
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may be more
susceptible to damage because very small parametric changes could cause the device not to meet its published specifications.
ORDERING INFORMATION (1)
PRODUCT
VOUT
XX is nominal output voltage (01 = Adjustable). (2)
YYY is package designator.
Z is package quantity.
TPS7A30xx yyy z
(1)
For the most current package and ordering information see the Package Option Addendum at the end of this document, or visit the
device product folder on www.ti.com.
For fixed -1.2V operation, tie FB to OUT.
(2)
ABSOLUTE MAXIMUM RATINGS (1)
Over operating free-air temperature range (unless otherwise noted).
VALUE
MIN
MAX
UNIT
IN pin to GND pin
–36
+0.3
V
OUT pin to GND pin
–33
+0.3
V
OUT pin to IN pin
–0.3
+36
V
–2
+0.3
V
FB pin to IN pin
–0.3
+36
V
EN pin to IN pin
–0.3
+36
V
EN pin to GND pin
–36
+36
V
NR/SS pin to IN pin
–0.3
+36
V
–2
+0.3
V
FB pin to GND pin
Voltage
NR/SS pin to GND pin
Current
Peak output
Temperature
Operating virtual junction, TJ
–40
+125
°C
Storage, Tstg
–65
+150
°C
1500
V
500
V
Human body model (HBM)
Electrostatic discharge rating
(1)
Internally limited
Charged device model (CDM)
Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only, and functional operation of the device at these or any other conditions beyond those indicated is not implied. Exposure to
absolute-maximum rated conditions for extended periods may affect device reliability.
THERMAL INFORMATION
TPS7A30xx
THERMAL METRIC (1)
DGN
UNITS
8 PINS
qJA
Junction-to-ambient thermal resistance
55.09
qJC(top)
Junction-to-case(top) thermal resistance
8.47
qJB
Junction-to-board thermal resistance
yJT
Junction-to-top characterization parameter
0.36
yJB
Junction-to-board characterization parameter
14.6
qJC(bottom)
Junction-to-case(bottom) thermal resistance
—
(1)
—
°C/W
For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.
DISSIPATION RATINGS
(1)
2
BOARD
PACKAGE
RqJA
RqJC
DERATING FACTOR
ABOVE TA = +25°C
TA ≤ +25°C POWER
RATING
TA = +70°C POWER
RATING
TA = +85°C POWER
RATING
High-K (1)
DGN
55.09°C/W
8.47°C/W
16.6mW/°C
1.83W
1.08W
0.833W
The JEDEC High-K (2s2p) board design used to derive this data was a 3-inch x 3-inch multilayer board with 2-ounce internal power and
ground planes and 2-ounce copper traces on top and bottom of the board.
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TPS7A30xx
www.ti.com
SBVS125 – AUGUST 2010
ELECTRICAL CHARACTERISTICS (1)
At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2µF, COUT = 2.2µF,
CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted.
TPS7A30xx
PARAMETER
TEST CONDITIONS
MIN
TYP
MAX
UNIT
–3.0
V
–1.184
–1.166
V
VIN
Input voltage range
VREF
Internal reference
TJ = +25°C, VNR/SS = VREF
–1.202
Output voltage range (2)
|VIN| ≥ |VOUT(NOM)| + 1.0V
–33.0
VREF
V
Nominal accuracy
TJ = +25°C, |VIN| = |VOUT(NOM)| + 0.5V
–1.5
+1.5
%VOUT
Overall accuracy
|VOUT(NOM)| + 1.0V ≤ |VIN| ≤ 35V
1mA ≤ IOUT ≤ 200mA
–2.5
+2.5
%VOUT
DVOUT(DVIN)
VOUT(NOM)
Line regulation
TJ = +25°C, |VOUT(NOM)| + 1.0V ≤ |VIN| ≤ 35V
0.14
%VOUT
DVOUT(DIOUT)
VOUT(NOM)
Load regulation
TJ = +25°C, 1mA ≤ IOUT ≤ 200mA
0.04
%VOUT
VIN = 95% VOUT(NOM), IOUT = 100mA
216
VIN = 95% VOUT(NOM), IOUT = 200mA
325
600
mV
330
500
mA
55
100
mA
VOUT
|VDO|
Dropout voltage
ILIM
Current limit
IGND
Ground current
|ISHDN|
Shutdown supply current
I FB
Feedback current (3)
|IEN|
Enable current
–35.0
VOUT = 90% VOUT(NOM)
220
IOUT = 0mA
IOUT = 100mA
950
VEN = +0.4V
1.0
VEN = –0.4V
mV
mA
3.0
mA
1.0
3.0
mA
14
100
nA
VEN = |VIN| = |VOUT(NOM)| + 1.0V
0.48
1.0
mA
VIN = VEN = –35V
0.51
1.0
mA
VIN = –35V, VEN = +15V
0.50
1.0
mA
+15
V
TJ = –40°C to +125°C
+2.0
TJ = –40°C to +85°C
+1.8
+15
0
+0.4
V
V+EN_HI
Positive enable high-level voltage
V+EN_LO
Positive enable low- level voltage
V–EN_HI
Negative enable high-level voltage
VIN
–2.0
V
V–EN_LO
Negative enable low- level voltage
–0.4
0
V
VNOISE
Output noise voltage
PSRR
Power-supply rejection ratio
TSD
Thermal shutdown temperature
TJ
Operating junction temperature
range
(1)
(2)
(3)
(4)
VIN = –3V, VOUT(NOM) = VREF, COUT = 10mF,
CNR/SS = 10nF, BW = 10Hz to 100kHz
15.1
mVRMS
VIN = –6.2V, VOUT(NOM) = –5V, COUT = 10mF,
CNR/SS = CBYP (4) = 10nF, BW = 10Hz to
100kHz
17.5
mVRMS
VIN = –6.2V, VOUT(NOM) = –5V, COUT = 10mF,
CNR/SS = CBYP (4) = 10nF, f = 120Hz
72
dB
Shutdown, temperature increasing
+170
°C
Reset, temperature decreasing
+150
°C
–40
+125
°C
At operating conditions, VIN ≤ 0V, VOUT(NOM) ≤ VREF ≤ 0V. At regulation, VIN ≤ VOUT(NOM) – |VDO|. IOUT > 0 flows from OUT to IN.
To ensure stability at no load conditions, a current from the feedback resistive network equal to or greater than 5mA is required.
IFB > 0 flows into the device.
CBYP refers to a bypass capacitor connected to the FB and OUT pins.
Copyright © 2010, Texas Instruments Incorporated
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SBVS125 – AUGUST 2010
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DEVICE INFORMATION
FUNCTIONAL BLOCK DIAGRAM
GND
EN
Enable
FB
Bandgap
NR/SS
Antisaturation
OUT
Error
Amp
Pass
Device
Thermal
Shutdown
Current
Limit
IN
TYPICAL APPLICATION CIRCUIT
VIN
EN
VOUT
OUT
IN
CIN
10mF
CBYP
10nF
TPS7A3001
R1
FB
R2
CNR/SS
10nF
NR/SS
GND
Where:
COUT
10mF
VOUT
³ 5mA, and
R1 + R2
R1 = R2
VOUT
-1
VREF
Maximize PSRR Performance and Minimize RMS Noise
4
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Copyright © 2010, Texas Instruments Incorporated
TPS7A30xx
www.ti.com
SBVS125 – AUGUST 2010
PIN CONFIGURATION
DGN PACKAGE
MSOP-8
(TOP VIEW)
OUT
FB
NC
GND
1
2
3
4
8
7
6
5
IN
DNC
NR/SS
EN
PIN DESCRIPTIONS
TPS7A30xx
NAME
NO.
OUT
1
Regulator output. A capacitor ≥ 2.2µF must be tied from this pin to ground to assure stability.
DESCRIPTION
FB
2
This pin is the input to the control-loop error amplifier. It is used to set the output voltage of the device.
NC
3
Not internally connected. This pin must either be left open or tied to GND.
GND
4
Ground
EN
5
This pin turns the regulator on or off. If VEN ≥ V+EN_HI or VEN ≤ V–EN_HI, the regulator is enabled.
If V+EN_LO ≥ VEN ≥ V–EN_LO, the regulator is disabled. The EN pin can be connected to IN, if not used. |VEN| ≤ |VIN|.
NR/SS
6
Noise reduction pin. Connecting an external capacitor to this pin bypasses noise generated by the internal bandgap.
This capacitor allows RMS noise to be reduced to very low levels and also controls the soft-start function.
DNC
7
DO NOT CONNECT. Do not route this pin to any electrical net, not even GND or IN.
IN
8
Input supply
PowerPAD
Must either be left open or tied to GND. Solder to printed circuit board (PCB) plane to enhance thermal performance.
Copyright © 2010, Texas Instruments Incorporated
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TPS7A30xx
SBVS125 – AUGUST 2010
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TYPICAL CHARACTERISTICS
At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2mF,
COUT = 2.2mF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted.
FEEDBACK VOLTAGE vs INPUT VOLTAGE
FEEDBACK CURRENT vs TEMPERATURE
100
-1.165
90
80
70
IFB (nA)
VFB (V)
-1.17
-1.175
+125°C
+105°C
+85°C
+25°C
-40°C
-1.18
60
50
40
30
20
10
0
-1.185
-40
-35
-30
-25
-20
VIN (V)
-15
-10
-5
0
-40 -25 -10
5
Figure 1.
80
95
110 125
Figure 2.
GROUND CURRENT vs INPUT VOLTAGE
GROUND CURRENT vs INPUT VOLTAGE
2500
1200
0mA
10mA
50mA
100mA
200mA
2000
TJ = +25°C
1000
800
1500
IGND (mA)
IGND (mA)
20 35 50 65
Temperature (°C)
1000
600
+125°C
+105°C
+85°C
+25°C
-40°C
400
500
200
IOUT = 100mA
0
0
-40
-35
-30
-25
-20
VIN (V)
-15
-10
-5
0
-40
-35
-30
Figure 3.
-25
-20
VIN (V)
-15
-10
-5
0
Figure 4.
GROUND CURRENT vs OUTPUT CURRENT
ENABLE CURRENT vs ENABLE VOLTAGE
2500
1000
+125°C
+25°C
-40°C
800
2000
600
IEN (nA)
IGND (mA)
400
1500
1000
+125°C
+105°C
+85°C
+25°C
-40°C
500
0
0
-200
-400
-600
-800
-1000
0
20
40
60
80 100 120 140 160 180 200
IOUT (mA)
Figure 5.
6
200
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-35
-25
-15
5
-5
VEN (V)
15
25
35
Figure 6.
Copyright © 2010, Texas Instruments Incorporated
TPS7A30xx
www.ti.com
SBVS125 – AUGUST 2010
TYPICAL CHARACTERISTICS (continued)
At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2mF,
COUT = 2.2mF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted.
QUIESCENT CURRENT vs INPUT VOLTAGE
SHUTDOWN CURRENT vs INPUT VOLTAGE
100
3.5
90
+125°C
+105°C
+85°C
+25°C
-40°C
3
80
2.5
ISHDN (mA)
IQ (mA)
70
60
50
40
+125°C
+105°C
+85°C
+25°C
-40°C
30
20
IOUT = 0mA
10
2
1.5
1
0.5
VEN = -0.4V
0
0
-40
-35
-30
-25
-20
VIN (V)
-15
-10
-5
0
-40
-35
-30
Figure 7.
-20
VIN (V)
-15
-10
-5
0
Figure 8.
DROPOUT VOLTAGE vs OUTPUT CURRENT
DROPOUT VOLTAGE vs TEMPERATURE
450
500
400
450
350
400
350
VDO (mV)
300
VDO (mV)
-25
250
200
+125°C
+105°C
+85°C
+25°C
-40°C
150
100
50
10mA
50mA
100mA
200mA
300
250
200
150
100
50
0
0
0
20
40
60
80 100 120 140 160 180 200
IOUT (mA)
-40 -25 -10
5
Figure 9.
20 35 50 65
Temperature (°C)
80
95
110 125
Figure 10.
CURRENT LIMIT vs INPUT VOLTAGE
CURRENT LIMIT vs TEMPERATURE
450
500
VOUT = 90% VOUT(NOM)
400
450
350
400
ILIM (mA)
ILIM (mA)
300
250
200
+125°C
+105°C
+85°C
+25°C
-40°C
150
100
50
350
300
250
0
200
-10
-9
-8
-7
-6
VIN (V)
Figure 11.
Copyright © 2010, Texas Instruments Incorporated
-5
-4
-3
-40 -25 -10
5
20 35 50 65
Temperature (°C)
80
95
110 125
Figure 12.
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TYPICAL CHARACTERISTICS (continued)
At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2mF,
COUT = 2.2mF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted.
ENABLE THRESHOLD VOLTAGE vs TEMPERATURE
POWER-SUPPLY REJECTION RATIO vs COUT
90
2
ON
80
1
70
0.5
60
0
PSRR (dB)
VEN (V)
1.5
OFF
-0.5
50
40
30
-1
-1.5
20
ON
COUT = 10mF
VOUT = -5V
VIN = -6.2V
IOUT = 200mA
CNR/SS = 10nF
CBYP = 0mF
COUT = 2.2mF
10
-2
-40 -25 -10
5
20 35 50 65
Temperature (°C)
80
95
10
110 125
100
1k
Figure 13.
LINE REGULATION
POWER-SUPPLY REJECTION RATIO vs CNR/SS
+125°C
+105°C
+85°C
+25°C
-40°C
0.4
0.2
80
CNR/SS = 10nF
70
PSRR (dB)
0.6
VOUT(NOM) (%)
10M
90
0.8
0
-0.2
-0.4
60
50
40
30
-0.6
20
-0.8
-1
VOUT = -5V
VIN = -6.2V
IOUT = 200mA
COUT = 10mF
CBYP = 0mF
CNR/SS = 0nF
10
-40
-35
-30
-25
-20
VIN (V)
-15
-10
-5
0
10
100
1k
Figure 15.
10k
100k
Frequency (Hz)
1M
10M
Figure 16.
LOAD REGULATION
POWER-SUPPLY REJECTION RATIO vs CBYP
1
90
0.6
0.4
0.2
0
-0.2
-0.4
80
CBYP = 10nF
70
PSRR (dB)
+125°C
+105°C
+85°C
+25°C
-40°C
0.8
VOUT(NOM) (%)
1M
Figure 14.
1
60
50
40
30
-0.6
20
-0.8
-1
VOUT = -5V
VIN = -6.2V
IOUT = 200mA
CNR/SS = 10nF
COUT = 10mF
CBYP = 0nF
10
0
20
40
60
80 100 120 140 160 180 200
IOUT (mA)
Figure 17.
8
10k
100k
Frequency (Hz)
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10
100
1k
100k
10k
Frequency (Hz)
1M
10M
Figure 18.
Copyright © 2010, Texas Instruments Incorporated
TPS7A30xx
www.ti.com
SBVS125 – AUGUST 2010
TYPICAL CHARACTERISTICS (continued)
At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2mF,
COUT = 2.2mF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted.
Output Spectral Noise Density (mV/ÖHz)
OUTPUT SPECTRAL NOISE DENSITY vs OUTPUT CURRENT
10
VOUT = -1.2V
VIN = -3V
CNR/SS = 10nF
COUT = 10mF
1
RMS NOISE
IOUT
10Hz to 100kHz
100Hz to 100kHz
1mA
15.13
14.73
200mA
17.13
16.71
IOUT = 200mA
0.1
IOUT = 1mA
0.01
10
100
1k
Frequency (Hz)
10k
100k
Figure 19.
Output Spectral Noise Density (mV/ÖHz)
OUTPUT SPECTRAL NOISE DENSITY vs CNR/SS
10
VOUT = -1.2V
VIN = -3V
IOUT = 200mA
COUT = 10mF
CNR/SS = 0nF
1
RMS NOISE
CNR/SS
10Hz to 100kHz
100Hz to 100kHz
0nF
80.00
79.83
10nF
17.29
16.81
0.1
CNR/SS = 10nF
0.01
10
100
1k
Frequency (Hz)
10k
100k
Figure 20.
Output Spectral Noise Density (mV/ÖHz)
OUTPUT SPECTRAL NOISE DENSITY vs VOUT(NOM)
10
VOUT(NOM) = -5V
1
IOUT = 1mA
CNR/SS = 10nF
CBYP = 10nF
COUT = 10mF
RMS NOISE
VOUT(NOM)
10Hz to 100kHz
100Hz to 100kHz
-5V
17.50
15.04
-1.2V
15.13
14.73
0.1
VOUT(NOM) = -1.2V
0.01
10
100
1k
Frequency (Hz)
10k
100k
Figure 21.
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TYPICAL CHARACTERISTICS (continued)
At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2mF,
COUT = 2.2mF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted.
CAPACITOR-PROGRAMMABLE SOFT START
VOUT = -1.2V
VIN = -3V
IOUT = 1mA
CIN = COUT = 2.2mF
CNR/SS = 0pF
VOUT
1V/div
1V/div
CAPACITOR-PROGRAMMABLE SOFT START
VOUT
VEN
Time (10ms/div)
Time (20ms/div)
Figure 22.
Figure 23.
CAPACITOR-PROGRAMMABLE SOFT START
CAPACITOR-PROGRAMMABLE SOFT START
VOUT = -1.2V
VIN = -3V
IOUT = 1mA
CIN = COUT = 2.2mF
CNR/SS = 1nF
VOUT
VEN
VEN
Time (100ms/div)
Time (1ms/div)
Figure 24.
Figure 25.
LINE TRANSIENT RESPONSE
LINE TRANSIENT RESPONSE
VIN
VIN = -20V to -4.3V
IOUT = 200mA
COUT = 2.2mF
VIN = -4.3V to -20V
IOUT = 200mA
COUT = 2.2mF
5V/div
5V/div
VOUT = -1.2V
VIN = -3V
IOUT = 1mA
CIN = COUT = 2.2mF
CNR/SS = 10nF
VOUT
1V/div
1V/div
VEN
VOUT = -1.2V
VIN = -3V
IOUT = 1mA
CIN = COUT = 2.2mF
CNR/SS = 100pF
10
20mV/div
20mV/div
VIN
VOUT
VOUT
Time (10ms/div)
Time (10ms/div)
Figure 26.
Figure 27.
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TPS7A30xx
www.ti.com
SBVS125 – AUGUST 2010
TYPICAL CHARACTERISTICS (continued)
At TJ = –40°C to +125°C, |VIN| = |VOUT(NOM)| + 1.0V or |VIN| = 3.0V (whichever is greater), VEN = VIN, IOUT = 1mA, CIN = 2.2mF,
COUT = 2.2mF, CNR/SS = 0nF, and the FB pin tied to OUT, unless otherwise noted.
50mV/div
200mA/div
LOAD TRANSIENT RESPONSE
IOUT
VOUT
VIN = -3.0V
IOUT = 1mA to 200mA
COUT = 2.2mF
Time (100ms/div)
Figure 28.
Copyright © 2010, Texas Instruments Incorporated
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TPS7A30xx
SBVS125 – AUGUST 2010
www.ti.com
THEORY OF OPERATION
GENERAL DESCRIPTION
The TPS7A30xx belongs to a family of new
generation linear regulators that use an innovative
bipolar process to achieve ultralow-noise and very
high PSRR levels at a wide input voltage range.
These features, combined with a high thermal
performance MSOP-8 with PowerPAD package make
this device ideal for high-performance analog
applications.
ADJUSTABLE OPERATION
VEN
VIN
The TPS7A3001 has an output voltage range of
–1.174 to –33V. The nominal output voltage of the
device is set by two external resistors, as shown in
Figure 29.
Time (20ms/div)
Figure 30. Enable Pin Positive/Negative
Threshold
VOUT
VIN
OUT
IN
CIN
10mF
EN
CBYP
10nF
TPS7A3001
R1
FB
R2
CNR/SS
10nF
NR/SS
CAPACITOR RECOMMENDATIONS
COUT
10mF
GND
Figure 29. Adjustable Operation for Maximum AC
Performance
R1 and R2 can be calculated for any output voltage
range using the formula shown in Equation 1. To
ensure stability under no load conditions, this
resistive network must provide a current equal to or
greater than 5mA.
VOUT
VOUT
³ 5mA
R1 = R2
- 1 , where
R1 + R2
VREF
(1)
If greater voltage accuracy is required, take into
account the output voltage offset contributions
because of the feedback pin current and use 0.1%
tolerance resistors.
ENABLE PIN OPERATION
The TPS7A30xx provides a dual polarity enable pin
(EN) that turns on the regulator when |VEN| > 2.0V,
whether the voltage is positive or negative, as shown
in Figure 30.
This functionality allows for different system power
management topologies:
• Connecting the EN pin directly to a negative
voltage, such as VIN, or
• Connecting the EN pin directly to a positive
voltage, such as the output of digital logic circuitry.
12
VOUT
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Low ESR capacitors should be used for the input,
output, noise reduction, and bypass capacitors.
Ceramic capacitors with X7R and X5R dielectrics are
preferred. These dielectrics offer more stable
characteristics. Ceramic X7R capacitors offer
improved over-temperature performance, while
ceramic X5R capacitors are the most cost-effective
and are available in higher values.
Note that high ESR capacitors may degrade PSRR.
INPUT AND OUTPUT CAPACITOR
REQUIREMENTS
The TPS7A30xx family of negative, high-voltage
linear regulators achieve stability with a minimum
input and output capacitance of 2.2mF; however, it is
highly recommended to use a 10mF capacitor to
maximize ac performance.
NOISE REDUCTION AND BYPASS
CAPACITOR REQUIREMENTS
Although noise reduction and bypass capacitors
(CNR/SS and CBYP, respectively) are not needed to
achieve stability, it is highly recommended to use
0.01mF capacitors to minimize noise and maximize ac
performance.
MAXIMUM AC PERFORMANCE
In order to maximize noise and PSRR performance, it
is recommended to include 10mF or higher input and
output capacitors, and 0.01mF noise reduction and
bypass capacitors, as shown in Figure 29. The
solution shown delivers minimum noise levels of
15.1mVRMS and power-supply rejection levels above
55dB from 10Hz to 700kHz; see Figure 18 and
Figure 19.
Copyright © 2010, Texas Instruments Incorporated
TPS7A30xx
www.ti.com
OUTPUT NOISE
The TPS7A30xx provides low output noise when a
noise reduction capacitor (CNR/SS) is used.
The noise reduction capacitor serves as a filter for the
internal reference. By using a 0.01mF noise reduction
capacitor, the output noise is reduced by almost 80%
(from 80mVRMS to 17mVRMS); see Figure 20.
SBVS125 – AUGUST 2010
Additionally, ac performance can be maximized by
adding a 0.01mF bypass capacitor (CBYP) from the FB
pin to the OUT pin. This capacitor greatly improves
power-supply rejection at lower frequencies, for the
band from 10Hz to 200kHz; see Figure 18.
TPS7A30xx low output voltage noise makes it an
ideal solution for powering noise-sensitive circuitry.
The very high power-supply rejection of the
TPS7A30xx makes it a good choice for powering
high-performance
analog
circuitry,
such
as
operational amplifiers, ADCs, DACS, and audio
amplifiers.
POWER-SUPPLY REJECTION
TRANSIENT RESPONSE
The 0.01mF noise reduction capacitor greatly
improves
TPS7A30xx
power-supply
rejection,
achieving up to 20dB of additional power-supply
rejection for frequencies between 110Hz and
400KHz.
As with any regulator, increasing the size of the
output capacitor reduces over/undershoot magnitude
but increases duration of the transient response.
Copyright © 2010, Texas Instruments Incorporated
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13
TPS7A30xx
SBVS125 – AUGUST 2010
www.ti.com
APPLICATION INFORMATION
POWER FOR PRECISION ANALOG
One of the primary TPS7A30xx applications is to
provide
ultralow
noise
voltage
rails
to
high-performance analog circuitry in order to
maximize system accuracy and precision.
In conjunction with its positive counterpart, the
TPS7A49xx family of positive high-voltage linear
regulators, the TPS7A30xx family of negative high
voltage linear regulators provides ultralow noise
positive
and
negative
voltage
rails
to
high-performance
analog
circuitry,
such
as
operational amplifiers, ADCs, DACs, and audio
amplifiers.
Because of the ultralow noise levels at high voltages,
analog circuitry with high-voltage input supplies can
be
used.
This
characteristic
allows
for
high-performance analog solutions to optimize the
voltage range, maximizing system accuracy.
The TPS7A30xx offers a wide-bandwidth, very-high
power-supply rejection ratio. This specification makes
it ideal for post dc/dc converter filtering, as shown in
Figure 31. It is highly recommended to use the
maximum performance schematic shown in
Figure 29. Also, verify that the fundamental frequency
(and its first harmonic, if possible) is within the
bandwidth of the regulator PSRR, shown in
Figure 18.
+18V
DC/DC converters are the preferred solution to step
up or down a voltage rail when current consumption
is not negligible. They offer high efficiency with
minimum heat generation, but they have one primary
disadvantage: they introduce a high-frequency
component, and the associated harmonics, on top of
the dc output signal.
This high-frequency component, if not filtered
properly, degrades analog circuitry performance,
reducing overall system accuracy and precision.
OUT
+15V
TPS7A49
POST DC/DC CONVERTER FILTERING
Most of the time, the voltage rails available in a
system do not match the voltage specifications
demanded by one or more of its circuits; these rails
must be stepped up or down, depending on specific
voltage requirements.
IN
-18V
EN
GND
IN
OUT
-15V
TPS7A30
EN
GND
EVM
Figure 31. Post DC/DC Converter Regulation to
High-Performance Analog Circuitry
AUDIO APPLICATIONS
Audio applications are extremely sensitive to any
distortion and noise in the audio band from 20Hz to
20kHz. This stringent requirement demands clean
voltage rails to power critical high-performance audio
systems.
The very-high power-supply rejection ratio (> 55dB)
and low noise at the audio band of the TPS7A30xx
maximize performance for audio applications; see
Figure 18.
14
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TPS7A30xx
www.ti.com
SBVS125 – AUGUST 2010
LAYOUT
PACKAGE MOUNTING
Solder pad footprint recommendations for the
TPS7A30xx are available at the end of this product
datasheet and at www.ti.com.
BOARD LAYOUT RECOMMENDATIONS TO
IMPROVE PSRR AND NOISE PERFORMANCE
To improve ac performance such as PSRR, output
noise, and transient response, it is recommended that
the board be designed with separate ground planes
for IN and OUT, with each ground plane connected
only at the GND pin of the device. In addition, the
ground connection for the output capacitor should
connect directly to the GND pin of the device.
Equivalent series inductance (ESL) and equivalent
series resistance (ESR) must be minimized in order
to maximize performance and ensure stability. Every
capacitor (CIN, COUT, CNR/SS, CBYP) must be placed as
close as possible to the device and on the same side
of the printed circuit board (PCB) as the regulator
itself.
Do not place any of the capacitors on the opposite
side of the PCB from where the regulator is installed.
The use of vias and long traces is strongly
discouraged because they may impact system
performance negatively and even cause instability.
If possible, and to ensure the maximum performance
denoted in this product datasheet, use the same
layout pattern used for TPS7A30 evaluation board,
available at www.ti.com.
THERMAL PROTECTION
Thermal protection disables the output when the
junction temperature rises to approximately +170°C,
allowing the device to cool. When the junction
temperature cools to approximately +150°C, the
output circuitry is enabled. Depending on power
dissipation, thermal resistance, and ambient
temperature, the thermal protection circuit may cycle
on and off. This cycling limits the dissipation of the
regulator, protecting it from damage as a result of
overheating.
Any tendency to activate the thermal protection circuit
indicates excessive power dissipation or an
inadequate heatsink. For reliable operation, junction
temperature should be limited to a maximum of
+125°C. To estimate the margin of safety in a
complete design (including heatsink), increase the
ambient temperature until the thermal protection is
triggered; use worst-case loads and signal conditions.
For good reliability, thermal protection should trigger
Copyright © 2010, Texas Instruments Incorporated
at least +35°C above the maximum expected ambient
condition of your particular application. This
configuration produces a worst-case junction
temperature of +125°C at the highest expected
ambient temperature and worst-case load.
The internal protection circuitry of the TPS7A30xx
has been designed to protect against overload
conditions. It was not intended to replace proper
heatsinking. Continuously running the TPS7A30xx
into thermal shutdown degrades device reliability.
POWER DISSIPATION
The ability to remove heat from the die is different for
each
package
type,
presenting
different
considerations in the PCB layout. The PCB area
around the device that is free of other components
moves the heat from the device to the ambient air.
Performance data or JEDEC low- and high-K boards
are given in the Dissipation Ratings Table. Using
heavier copper increases the effectiveness in
removing heat from the device. The addition of plated
through-holes to heat dissipating layers also improves
the heatsink effectiveness.
Power dissipation depends on input voltage and load
conditions. Power dissipation (PD) is equal to the
product of the output current times the voltage drop
across the output pass element, as shown in
Equation 2:
PD = (VIN - VOUT) IOUT
(2)
SUGGESTED LAYOUT AND SCHEMATIC
Layout is a critical part of good power-supply design.
There are several signal paths that conduct
fast-changing currents or voltages that can interact
with stray inductance or parasitic capacitance to
generate noise or degrade the power-supply
performance. To help eliminate these problems, the
IN pin should be bypassed to ground with a low ESR
ceramic bypass capacitor with a X5R or X7R
dielectric.
The GND pin should be tied directly to the PowerPAD
under the IC. The PowerPAD should be connected to
any internal PCB ground planes using multiple vias
directly under the IC.
It may be possible to obtain acceptable performance
with alternate PCB layouts; however, the layout
shown in Figure 32 and the schematic shown in
Figure 33 have been shown to produce good results
and are meant as a guideline.
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15
TPS7A30xx
SBVS125 – AUGUST 2010
www.ti.com
Figure 32. PCB Layout Example
U1 TPS7A30XXDGN
5
6
C4
7
8
Vin
J1
4
GND
EN
3
NR/SS
NC
DNC
FB
2
IN
PwPd
J1
1
OUT
C1
J7
GND
R1
9
J4
C2
C3
R3
Figure 33. Schematic for PCB Layout Example
16
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Copyright © 2010, Texas Instruments Incorporated
PACKAGE OPTION ADDENDUM
www.ti.com
16-Aug-2010
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package
Drawing
Pins
Package Qty
Eco Plan
(2)
Lead/
Ball Finish
MSL Peak Temp
(3)
Samples
(Requires Login)
TPS7A3001DGNR
ACTIVE
MSOPPowerPAD
DGN
8
2500
Green (RoHS
& no Sb/Br)
CU NIPDAU Level-2-260C-1 YEAR
Purchase Samples
TPS7A3001DGNT
ACTIVE
MSOPPowerPAD
DGN
8
250
Green (RoHS
& no Sb/Br)
CU NIPDAU Level-2-260C-1 YEAR
Request Free Samples
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
(3)
MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
Addendum-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
14-Aug-2010
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device
Package Package Pins
Type Drawing
SPQ
Reel
Reel
A0
Diameter Width (mm)
(mm) W1 (mm)
B0
(mm)
K0
(mm)
P1
(mm)
W
Pin1
(mm) Quadrant
TPS7A3001DGNR
MSOPPower
PAD
DGN
8
2500
330.0
12.4
5.3
3.4
1.4
8.0
12.0
Q1
TPS7A3001DGNT
MSOPPower
PAD
DGN
8
250
180.0
12.4
5.3
3.4
1.4
8.0
12.0
Q1
Pack Materials-Page 1
PACKAGE MATERIALS INFORMATION
www.ti.com
14-Aug-2010
*All dimensions are nominal
Device
Package Type
Package Drawing
Pins
SPQ
Length (mm)
Width (mm)
Height (mm)
TPS7A3001DGNR
MSOP-PowerPAD
DGN
8
2500
346.0
346.0
29.0
TPS7A3001DGNT
MSOP-PowerPAD
DGN
8
250
190.5
212.7
31.8
Pack Materials-Page 2
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