TI EMK212BJ474MG Unregulated 60-ma charge pump voltage inverter Datasheet

TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
features
applications
D Inverts Input Supply Voltage
D Up to 60-mA Output Current
D Only Three Small 1-µF Ceramic Capacitors
D
D
D
D
D
D
Needed
D Input Voltage Range From 1.6 V to 5.5 V
D PowerSave-Mode for Improved Efficiency
D
D
D
D
at Low Output Currents (TPS60400)
Device Quiescent Current Typical 100 µA
Integrated Active Schottky-Diode for
Start-Up Into Load
Small 5-Pin SOT23 Package
Evaluation Module Available
TPS60400EVM–178
LCD Bias
GaAs Bias for RF Power Amps
Sensor Supply in Portable Instruments
Bipolar Amplifier Supply
Medical Instruments
Battery-Operated Equipment
DBV PACKAGE
(TOP VIEW)
OUT
1
IN
2
CFLY–
3
5
CFLY+
4
GND
description
The TPS6040x is a family of devices that generate an unregulated negative output voltage from an input voltage
ranging from 1.6 V to 5.5 V. The devices are typically supplied by a preregulated supply rail of 5 V or 3.3 V. Due
to its wide input voltage range, two or three NiCd, NiMH, or alkaline battery cells, as well as one Li-Ion cell can
also power them.
Only three external 1-µF capacitors are required to build a complete dc/dc charge pump inverter. Assembled
in a 5-pin SOT23 package, the complete converter can be built on a 50 mm2 board area. Additional board area
and component count reduction is achieved by replacing the Schottky diode that is typically needed for start-up
into load by integrated circuitry.
The TPS6040x can deliver a maximum output current of 60 mA with a typical conversion efficiency of greater
than 90% over a wide output current range. Three device options with 20-kHz, 50-kHz, and 250-kHz fixed
frequency operation are available. One device comes with a variable switching frequency to reduce operating
current in applications with a wide load range and enables the design with low-value capacitors.
typical application circuit
TPS60400
C(fly)
1 µF
CI
1 µF
IO = 60 mA
5
CFLY–
2
0
TPS60400
IN
OUT
GND
4
IO = 30 mA
–1
CFLY+
1
CO
1 µF
Output
–1.6 V to –5 V,
Max 60 mA
V O – Output Voltage – V
3
Input
1.6 V to 5.5 V
OUTPUT VOLTAGE
vs
INPUT VOLTAGE
IO = 1 mA
–2
–3
–4
TA = 25°C
–5
0
1
2
3
4
VI – Input Voltage – V
5
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.
Copyright  2001, Texas Instruments Incorporated
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
AVAILABLE OPTIONS
PART NUMBER†
MARKING DBV
PACKAGE
TYPICAL FLYING CAPACITOR
[µF]
FEATURE
TPS60400DBV
PFKI
1
Variable switching frequency
50 kHz–250 kHz
TPS60401DBV
PFLI
10
Fixed frequency 20 kHz
TPS60402DBV
PFMI
3.3
Fixed frequency 50 kHz
TPS60403DBV
PFNI
1
Fixed frequency 250 kHz
† The DBV package is available taped and reeled. Add R suffix to device type (e.g. TPS60400DBVR) to order quantities of
3000 devices per reel. Add T suffix to device type (e.g. TPS60400DBVT) to order quantities of 250 devices per reel.
TPS60400 functional block diagram
VI
VI – VCFLY+ < 0.5 V
VI
MEAS
VI < 1 V
VO > Vbe
R
Start
FF
Q
DC_ Startup
VO
Q1
OSC
CHG
OSC
VO
MEAS
50 kHz
Q
Phase
Generator
+
Q
Q2
VO
Q4
C(fly)
VO > –1 V
VI
VI
S
B
Q3
Q5
GND
VO
VCO_CONT
VI / VO
MEAS
DC_ Startup
VO < –VI – Vbe
Terminal Functions
TERMINAL
I/O
DESCRIPTION
NAME
NO.
CFLY+
5
Positive terminal of the flying capacitor C(fly)
CFLY–
3
Negative terminal of the flying capacitor C(fly)
GND
4
IN
2
I
Supply input. Connect to an input supply in the 1.6-V to 5.5-V range. Bypass IN to GND with a capacitor that has the
same value as the flying capacitor.
OUT
1
O
Power output with VO = –VI
Bypass OUT to GND with the output filter capacitor CO.
2
Ground
POST OFFICE BOX 655303
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
detailed description
operating principle
The TPS60400, TPS60401 charge pumps invert the voltage applied to their input. For the highest performance,
use low equivalent series resistance (ESR) capacitors (e.g., ceramic). During the first half-cycle, switches S2
and S4 open, switches S1 and S3 close, and capacitor (C(fly)) charges to the voltage at VI. During the second
half-cycle, S1 and S3 open, S2 and S4 close. This connects the positive terminal of C(fly) to GND and the
negative to VO. By connecting C(fly) in parallel, CO is charged negative. The actual voltage at the output is more
positive than –VI, since switches S1–S4 have resistance and the load drains charge from CO.
VI
S1
C(fly)
S4
VO (–VI)
1 µF
S2
CO
1 µF
S3
GND
GND
Figure 1. Operating Principle
charge-pump output resistance
The TPS6040x devices are not voltage regulators. The charge pumps output source resistance is
approximately 15 Ω at room temperature (with VI = 5 V), and VO approaches –5 V when lightly loaded. VO will
droop toward GND as load current increases.
VO = –(VI – RO × IO)
R
O
[
ƒosc
1
C
ǒ
) 4 2R
SWITCH
) ESR
(fly)
RO = output resistance of the converter
Ǔ ) ESRCO
(1)
CFLY
efficiency considerations
The power efficiency of a switched-capacitor voltage converter is affected by three factors: the internal losses
in the converter IC, the resistive losses of the capacitors, and the conversion losses during charge transfer
between the capacitors. The internal losses are associated with the IC’s internal functions, such as driving the
switches, oscillator, etc. These losses are affected by operating conditions such as input voltage, temperature,
and frequency. The next two losses are associated with the voltage converter circuit’s output resistance. Switch
losses occur because of the on-resistance of the MOSFET switches in the IC. Charge-pump capacitor losses
occur because of their ESR. The relationship between these losses and the output resistance is as follows:
PCAPACITOR LOSSES + PCONVERSION LOSSES = IO2 × RO
RSWITCH = resistance of a single MOSFET-switch inside the converter
fOSC = oscillator frequency
The first term is the effective resistance from an ideal switched-capacitor circuit. Conversion losses occur during
the charge transfer between C(fly) and CO when there is a voltage difference between them. The power loss is:
ƪ
P CONV.LOSS + 1
2
ǒ
Ǔ
ǒ
C (fly) V I2 * V O 2 ) 1 C O V RIPPLE2 * 2V OV RIPPLE
2
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Ǔƫ
ƒ osc
(2)
3
TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
efficiency considerations (continued)
The efficiency of the TPS6040x devices is dominated by their quiescent supply current at low output current and
by their output impedance at higher current.
h^
IO
IO ) IQ
ǒ
I
1* O
RO
VI
Ǔ
Where, IQ = quiescent current.
capacitor selection
To maintain the lowest output resistance, use capacitors with low ESR (see Table 1). The charge-pump output
resistance is a function of C(fly)’s and CO’s ESR. Therefore, minimizing the charge-pump capacitor’s ESR
minimizes the total output resistance. The capacitor values are closely linked to the required output current and
the output noise and ripple requirements. It is possible to only use 1-µF capacitors of the same type.
input capacitor (CI)
Bypass the incoming supply to reduce its ac impedance and the impact of the TPS6040x switching noise. The
recommended bypassing depends on the circuit configuration and where the load is connected. When the
inverter is loaded from OUT to GND, current from the supply switches between 2 x IO and zero. Therefore, use
a large bypass capacitor (e.g., equal to the value of C(fly)) if the supply has high ac impedance. When the inverter
is loaded from IN to OUT, the circuit draws 2 × IO constantly, except for short switching spikes. A 0.1-µF bypass
capacitor is sufficient.
flying capacitor (C(fly))
Increasing the flying capacitor’s size reduces the output resistance. Small values increases the output
resistance. Above a certain point, increasing C(fly)’s capacitance has a negligible effect, because the output
resistance becomes dominated by the internal switch resistance and capacitor ESR.
output capacitor (CO)
Increasing the output capacitor’s size reduces the output ripple voltage. Decreasing its ESR reduces both output
resistance and ripple. Smaller capacitance values can be used with light loads if higher output ripple can be
tolerated. Use the following equation to calculate the peak-to-peak ripple.
V
O(ripple)
+
I
f osc
O
Co
)2
I
O
ESR
CO
Table 1. Recommended Capacitor Values
4
DEVICE
VI
[V]
IO
[mA]
CI
[µF]
C(fly)
[µF]
CO
[µF]
TPS60400
1.8…5.5
60
1
1
1
TPS60401
1.8…5.5
60
10
10
10
TPS60402
1.8…5.5
60
3.3
3.3
3.3
TPS60403
1.8…5.5
60
1
1
1
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
detailed description (continued)
Table 2. Recommended Capacitors
MANUFACTURER
PART NUMBER
SIZE
CAPACITANCE
TYPE
Taiyo Yuden
EMK212BJ474MG
LMK212BJ105KG
LMK212BJ225MG
EMK316BJ225KL
LMK316BJ475KL
JMK316BJ106KL
0805
0805
0805
1206
1206
1206
0.47 µF
1 µF
2.2 µF
2.2 µF
4.7 µF
10 µF
Ceramic
Ceramic
Ceramic
Ceramic
Ceramic
Ceramic
TDK
C2012X5R1C105M
C2012X5R1A225M
C2012X5R1A335M
0805
0805
0805
1 µF
2.2 µF
3.3 µF
Ceramic
Ceramic
Ceramic
Table 3 contains a list of manufacturers of the recommended capacitors. Ceramic capacitors will provide the
lowest output voltage ripple because they typically have the lowest ESR-rating.
Table 3. Recommended Capacitor Manufacturers
MANUFACTURER
CAPACITOR TYPE
INTERNET
Taiyo Yuden
X7R/X5R ceramic
www.t-yuden.com
TDK
X7R/X5R ceramic
www.component.tdk.com
Vishay
X7R/X5R ceramic
www.vishay.com
Kemet
X7R/X5R ceramic
www.kemet.com
absolute maximum ratings over operating free-air temperature (unless otherwise noted)†
Voltage range:
IN to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to 5.5 V
OUT to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –5.0 V to 0.3 V
CFLY– to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0.3 V to (VO – 0.3 V)
CFLY+ to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –0.3 V to (VI + 0.3 V)
Continuous power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . See Dissipation Rating Table
Continuous output current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 80 mA
Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . –55°C to 150°C
Maximum junction temperature, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150°C
† 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 under “recommended operating conditions” is not
implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
DISSIPATION RATING TABLE
PACKAGE
TA < 25°C
POWER RATING
DERATING FACTOR
ABOVE TA = 25°C
TA = 70°C
POWER RATING
TA = 85°C
POWER RATING
DBV
437 mW
3.5 mW/°C
280 mW
227 mW
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
recommended operating conditions
MIN
Input voltage range, VI
NOM
1.8
Output current range at OUT, IO
MAX
UNIT
5.25
V
60
Input capacitor, CI
0
Flying capacitor, C(fly)
1
Output capacitor, CO
1
Operating junction temperature, TJ
–40
mA
µF
C(fly)
µF
100
µF
125
°C
electrical characteristics at CI = C(fly) = CO (according to Table 1), TC = –40°C to 85°C, VI = 5 V over
recommended operating free-air temperature range (unless otherwise noted)
PARAMETER
VI
Supply voltage range
IO
VO
Maximum output current at VO
TEST CONDITIONS
At TC = –40°C to 85°C,
At TC ≥ 0°C,
1.8
RL = 5 kΩ
1.6
Output voltage
Output voltage ripple
TPS60402
IO = 5 mA
TPS60403
V
mA
C(fly) = CO = 10 µF
20
C(fly) = CO = 3.3 µF
20
C(fly) = CO = 1 µF
15
270
65
190
120
270
425
700
TPS60403
60°C
At T ≤ 60°C,
135
VI = 5 V
210
TPS60403
TPS60400
6
A
µA
640
VCO version
30 50–250
350
TPS60401
13
20
28
TPS60402
30
50
70
150
TPS60403
Impedance at 25°C
25°C, VI = 5 V
µA
A
210
TPS60400
TPS60402
Internal switching frequency
mVP–P
125
TPS60401
fOSC
V
TPS60401
At VI = 5 V
UNIT
5.25
TPS60400
TPS60402
Quiescent current (no-load in
input
ut
current)
MAX
–VI
35
C(fly) = 1 µF, CO = 2.2 µF
TPS60401
IQ
RL = 5 kΩ
TYP
60
TPS60400
VP–P
MIN
250
300
TPS60400
CI = C(fly) = CO = 1 µF
12
15
TPS60401
CI = C(fly) = CO = 10 µF
12
15
TPS60402
CI = C(fly) = CO = 3.3 µF
12
15
TPS60403
CI = C(fly) = CO = 1 µF
12
15
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kHz
Ω
TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
TYPICAL CHARACTERISTICS
Table of Graphs
FIGURE
η
Efficiency
vs Output current at 3.3 V, 5 V
TPS60400, TPS60401, TPS60402, TPS60403
2, 3
II
Input current
vs Output current
TPS60400, TPS60401, TPS60402, TPS60403
4, 5
IS
Supply current
vs Input voltage
TPS60400, TPS60401, TPS60402, TPS60403
6, 7
Output resistance
vs Input voltage at –40°C, 0°C, 25°C, 85°C
TPS60400, CI = C(fly) = CO = 1 µF
TPS60401, CI = C(fly) = CO = 10 µF
TPS60402 , CI = C(fly) = CO = 3.3 µF
TPS60403, CI = C(fly) = CO = 1 µF
8, 9, 10,
11
VO
Output voltage
vs Output current at 25°C, VIN=1.8 V, 2.5 V, 3.3 V, 5 V
TPS60400, CI = C(fly) = CO = 1 µF
TPS60401, CI = C(fly) = CO = 10 µF
TPS60402 , CI = C(fly) = CO = 3.3 µF
TPS60403, CI = C(fly) = CO = 1 µF
12, 13,
14, 15
fOSC
Oscillator frequency
vs Temperature at VI = 1.8 V, 2.5 V, 3.3 V, 5 V
TPS60400, TPS60401, TPS60402, TPS60403
16, 17,
18, 19
fOSC
Oscillator frequency
vs Output current TPS60400 at 2 V, 3.3 V, 5.0 V
Output ripple and noise
VI = 5 V, IO = 30 mA, CI = C(fly) = CO = 1 µF (TPS60400)
VI = 5 V, IO = 30 mA, CI = C(fly) = CO = 10 µF (TPS60401)
VI = 5 V, IO = 30 mA, CI = C(fly) = CO = 3.3 µF (TPS60402)
VI = 5 V, IO = 30 mA, CI = C(fly) = CO = 1 µF (TPS60403)
TPS60400, TPS60401
TPS60402, TPS60403
EFFICIENCY
vs
OUTPUT CURRENT
EFFICIENCY
vs
OUTPUT CURRENT
100
100
TPS60400
VI = 5 V
95
TPS60403
VI = 5 V
95
TPS60401
VI = 5 V
TPS60402
VI = 5 V
90
85
Efficiency – %
90
Efficiency – %
20
21, 22
TPS60401
VI = 3.3 V
80
75
TPS60400
VI = 3.3 V
70
85
80
TPS60403
VI = 3.3 V
75
TPS60402
VI = 3.3 V
70
65
65
TA = 25°C
60
TA = 25°C
60
0
10
20
30 40 50 60 70 80
IO – Output Current – mA
90 100
0
10
Figure 2
20
30 40 50 60 70 80
IO – Output Current – mA
90 100
Figure 3
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
TYPICAL CHARACTERISTICS
TPS60400, TPS60401
INPUT CURRENT
vs
OUTPUT CURRENT
TPS60402, TPS60403
INPUT CURRENT
vs
OUTPUT CURRENT
100
100
TA = 25°C
TPS60400
VI = 5 V
I I – Input Current – mA
I I – Input Current – mA
TA = 25°C
10
TPS60401
VI = 5 V
TPS60401
VI = 2 V
1
TPS60403
VI = 5 V
10
TPS60403
VI = 2 V
1
TPS60402
VI = 5 V
TPS60400
VI = 2 V
0.1
0.1
TPS60402
VI = 2 V
1
10
IO – Output Current – mA
0.1
0.1
100
1
10
IO – Output Current – mA
Figure 4
Figure 5
TPS60400, TPS60401
TPS60402, TPS60403
SUPPLY CURRENT
vs
INPUT VOLTAGE
SUPPLY CURRENT
vs
INPUT VOLTAGE
0.6
0.6
IO = 0 mA
TA = 25°C
I DD – Supply Current – mA
IO = 0 mA
TA = 25°C
I DD – Supply Current – mA
100
0.4
0.2
0.4
TPS60403
0.2
TPS60400
TPS60402
TPS60401
0
0
1
2
3
VI – Input Voltage – V
4
0
5
0
Figure 6
8
1
2
3
VI – Input Voltage – V
Figure 7
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4
5
TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
TYPICAL CHARACTERISTICS
TPS60400
TPS60401
OUTPUT RESISTANCE
vs
INPUT VOLTAGE
OUTPUT RESISTANCE
vs
INPUT VOLTAGE
40
40
IO = 30 mA
CI = C(fly) = CO = 1 µF
30
30
ro – Output Resistance – Ω
ro – Output Resistance – Ω
35
IO = 30 mA
CI = C(fly) = CO = 10 µF
35
25
TA = 85°C
20
TA = 25°C
15
10
25
20
TA = 25°C
15
10
5
5
TA = –40°C
TA = –40°C
0
0
1
2
3
4
VI – Input Voltage – V
5
6
1
2
3
4
VI – Input Voltage – V
Figure 8
5
6
Figure 9
TPS60402
TPS60403
OUTPUT RESISTANCE
vs
INPUT VOLTAGE
OUTPUT RESISTANCE
vs
INPUT VOLTAGE
40
40
IO = 30 mA
CI = C(fly) = CO = 3.3 µF
30
25
TA = 25°C
20
TA = 85°C
15
10
TA = –40°C
5
IO = 30 mA
CI = C(fly) = CO = 1 µF
35
ro – Output Resistance – Ω
35
ro – Output Resistance – Ω
TA = 85°C
30
25
20
TA = 25°C
TA = 85°C
15
10
5
0
TA = –40°C
0
1
2
3
4
VI – Input Voltage – V
5
6
1
Figure 10
2
3
4
VI – Input Voltage – V
5
6
Figure 11
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
TYPICAL CHARACTERISTICS
TPS60400
TPS60401
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
0
0
TA = 25°C
–1
VI = 1.8 V
VI = 1.8 V
VO – Output Voltage – V
VO – Output Voltage – V
–1
TA = 25°C
VI = 2.5 V
–2
–3
VI = 3.3 V
–4
VI = 5 V
–5
–6
VI = 2.5 V
–2
VI = 3.3 V
–3
–4
VI = 5 V
–5
0
10
20
30
40
50
–6
60
0
10
IO – Output Current – mA
20
Figure 12
TPS60402
TPS60403
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
OUTPUT VOLTAGE
vs
OUTPUT CURRENT
60
50
60
TA = 25°C
–1
–1
VI = 1.8 V
VO – Output Voltage – V
VI = 1.8 V
VO – Output Voltage – V
50
0
TA = 25°C
VI = 2.5 V
–2
VI = 3.3 V
–3
–4
VI = 5 V
VI = 2.5 V
–2
VI = 3.3 V
–3
–4
VI = 5 V
–5
–5
–6
0
10
20
30
40
50
60
0
10
20
30
Figure 14
Figure 15
POST OFFICE BOX 655303
40
IO – Output Current – mA
IO – Output Current – mA
10
40
Figure 13
0
–6
30
IO – Output Current – mA
• DALLAS, TEXAS 75265
TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
TYPICAL CHARACTERISTICS
TPS60400
TPS60401
OSCILLATOR FREQUENCY
vs
FREE-AIR TEMPERATURE
OSCILLATOR FREQUENCY
vs
FREE-AIR TEMPERATURE
24
250
23.8
VI = 1.8 V
200
150
VI = 2.5 V
VI = 3.3 V
100
VI = 5 V
50
f osc– Oscillator Frequency – kHz
f osc– Oscillator Frequency – kHz
IO = 10 mA
IO = 10 mA
23.6
VI = 3.3 V
23.4
VI = 5 V
23.2
23
VI = 2.5 V
22.8
22.6
VI = 1.8 V
22.4
22.2
0
–40 –30 –20 –10 0
22
–40 –30 –20 –10 0
10 20 30 40 50 60 70 80 90
TA – Free-Air Temperature – °C
Figure 16
Figure 17
TPS60402
TPS60403
OSCILLATOR FREQUENCY
vs
FREE-AIR TEMPERATURE
OSCILLATOR FREQUENCY
vs
FREE-AIR TEMPERATURE
250
57
IO = 10 mA
VI = 5 V
240
VI = 5 V
VI = 3.3 V
55
54
VI = 2.5 V
53
52
VI = 1.8 V
51
50
f osc– Oscillator Frequency – kHz
56
f osc– Oscillator Frequency – kHz
10 20 30 40 50 60 70 80 90
TA – Free-Air Temperature – °C
VI = 3.3 V
230
VI = 2.5 V
220
210
VI = 1.8 V
200
190
180
170
IO = 10 mA
160
49
–40 –30 –20 –10 0
10 20 30 40 50 60 70 80 90
150
–40 –30 –20 –10 0
10 20 30 40 50 60 70 80 90
TA – Free-Air Temperature – °C
TA – Free-Air Temperature – °C
Figure 18
Figure 19
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
TYPICAL CHARACTERISTICS
TPS60400
TPS60401, TPS60402
OSCILLATOR FREQUENCY
vs
OUTPUT CURRENT
OUTPUT VOLTAGE
vs
TIME
300
VI = 5 V
IO = 30 mA
TPS60401
VI = 3.3 V
250
VI = 1.8 V
VO – Output Voltage – mV
f osc– Oscillator Frequency – kHz
TA = 25°C
200
VI = 5 V
150
100
50 mV/DIV
TPS60402
50
50 mV/DIV
0
0
10
20
30
40
50
60
70
80
90 100
20 µs/DIV
t – Time – µs
IO – Output Current – mA
Figure 20
Figure 21
TPS60400, TPS60403
OUTPUT VOLTAGE
vs
TIME
VO – Output Voltage – mV
VI = 5 V
IO = 30 mA
TPS60400
100 mV/DIV
TPS60403
50 mV/DIV
4 µs/DIV
t – Time – µs
Figure 22
12
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
voltage inverter
The most common application for these devices is a charge-pump voltage inverter (see Figure 23). This
application requires only two external components; capacitors C(fly) and CO, plus a bypass capacitor, if
necessary. Refer to the capacitor selection section for suggested capacitor types.
C(fly)
2
Input 5 V
CI
1 µF
1 µF
3
5
C1–
C1+
TPS60400
IN
OUT
GND
4
1
CO
1 µF
–5 V,
Max 60 mA
Figure 23. Typical Operating Circuit
For the maximum output current and best performance, three ceramic capacitors of 1 µF (TPS60400,
TPS60403) are recommended. For lower currents or higher allowed output voltage ripple, other capacitors can
also be used. It is recommended that the output capacitors has a minimum value of 1 µF. With flying capacitors
lower than 1 µF, the maximum output power will decrease.
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UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
RC-post filter
VI
C(fly)
1
2
3
1 µF
OUT
C1+
TPS60400
IN
C1–
GND
5
RP
4
VO (–VI)
CI
1 µF
CO
1 µF
CP
GND
GND
Figure 24. TPS60400 and TPS60401 With RC-Post Filter
An output filter can easily be formed with a resistor (RP) and a capacitor (CP). Cutoff frequency is given by:
ƒc +
1
2pR PC P
(1)
and ratio VO/VOUT is:
Ť Ť
VO
V OUT
+
1
Ǹ1 ) ǒ2pƒR C Ǔ
(2)
2
P P
with RP = 50 Ω, CP = 0.1 µF and f = 250 kHz:
Ť Ť
VO
V OUT
+ 0.125
The formula refers only to the relation between output and input of the ac ripple voltages of the filter.
LC-post filter
VI
C(fly)
1
2
3
1 µF
OUT
C1+
TPS60400
IN
C1–
GND
5
VOUT
LP
4
CI
1 µF
VO (–VI)
CO
1 µF
GND
CP
GND
Figure 25. LC-Post Filter
Figure 25 shows a configuration with a LC-post filter to further reduce output ripple and noise.
14
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UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
Table 4. Measurement Results on the TPS60400 (Typical)
CI
[µF]
C(fly)
[µF]
CO
[µF]
CERAMIC
CERAMIC
CERAMIC
1
1
60
1
5
60
5
60
5
5
CP
[µF]
BW = 500 MHz
VPOUT
VP–P[mV]
BW = 20 MHz
VPOUT
VP–P[mV]
VPOUT
VACeff [mV]
1
320
240
65
1
2.2
120
240
32
1
1
1
0.1 (X7R)
260
200
58
1
1
1
0.1
0.1 (X7R)
220
200
60
60
1
1
2.2
0.1
0.1 (X7R)
120
100
30
60
1
1
10
0.1
0.1 (X7R)
50
28
8
VI
[V]
IO(2)
( )
[mA]
5
60
5
LP
[µH]
CERAMIC
rail splitter
VI
C(fly)
1
2
3
1 µF
OUT
C1+
TPS60400
IN
C1–
GND
CI
1 µF
5
C3
1 µF
VO (–VI)
4
CO
1 µF
GND
GND
Figure 26. TPS60400 as a High-Efficiency Rail Splitter
A switched-capacitor voltage inverter can be configured as a high efficiency rail-splitter. This circuit provides a
bipolar power supply that is useful in battery powered systems to supply dual-rail ICs, like operational amplifiers.
Moreover, the SOT23-5 package and associated components require very little board space.
After power is applied, the flying capacitor (C(fly)) connects alternately across the output capacitors C3 and CO.
This equalizes the voltage on those capacitors and draws current from VI to VO as required to maintain the
output at 1/2 VI.
The maximum input voltage between VI and GND in the schematic (or between IN and OUT at the device itself)
must not exceed 6.5 V.
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UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
combined doubler/inverter
In the circuit of Figure 27, capacitors CI, C(fly), and CO form the inverter, while C1 and C2 form the doubler. C1
and C(fly) are the flying capacitors; CO and C2 are the output capacitors. Because both the inverter and doubler
use part of the charge-pump circuit, loading either output causes both outputs to decline toward GND. Make
sure the sum of the currents drawn from the two outputs does not exceed 60 mA. The maximum output current at
V(pos) must not exceed 30 mA. If the negative output is loaded, this current must be further reduced.
II ≈ –IO + 2 × IO(POS)
VI
C(fly)
1
2
3
+
1 µF
+
C1
OUT
C1+
TPS60400
IN
C1–
D2
5
V(pos)
+
–VI
4
GND
CI
1 µF
+
+
CO
1 µF
C2
GND
GND
Figure 27. TPS60400 as Doubler/Inverter
cascading devices
Two devices can be cascaded to produce an even larger negative voltage (see Figure 28). The unloaded output
voltage is normally –2 × VI, but this is reduced slightly by the output resistance of the first device multiplied by the
quiescent current of the second. When cascading more than two devices, the output resistance rises
dramatically.
VI
VO (–2 VI)
C(fly)
1
2
3
+
CI
1 µF
1 µF
C(fly)
OUT
C1+
TPS60400
IN
C1–
GND
1
5
2
4
3
+
1 µF
OUT
C1+
TPS60400
IN
C1–
GND
CO
1 µF
4
+
GND
CO
1 µF
GND
GND
Figure 28. Doubling Inverter
16
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
paralleling devices
Paralleling multiple TPS6040xs reduces the output resistance. Each device requires its own flying capacitor
(C(fly)), but the output capacitor (CO) serves all devices (see Figure 29). Increase CO’s value by a factor of n,
where n is the number of parallel devices. Equation 1 shows the equation for calculating output resistance.
VI
C(fly)
1
2
3
1 µF
OUT
C1+
TPS60400
IN
C1–
GND
C(fly)
5
1
2
4
3
1 µF
OUT
C1+
TPS60400
IN
C1–
GND
5
VO (–VI)
4
CI
1 µF
+
GND
CO
2.2 µF
GND
Figure 29. Paralleling Devices
active-Schottky diode
For a short period of time, when the input voltage is applied, but the inverter is not yet working, the output
capacitor is charged positive by the load. To prevent the output being pulled above GND, a Schottky diode must
be added in parallel to the output. The function of this diode is integrated into the TPS6040x devices, which gives
a defined startup performance and saves board space.
A current sink and a diode in series can approximate the behavior of a typical, modern operational amplifier.
Figure 30 shows the current into this typical load at a given voltage. The TPS6040x devices are optimized to
start into these loads.
VI
C(fly)
5
1 µF
C1+
+V
Load Current
Typical
Load
3
–V
C1–
60 mA
TPS60400
2
CI
1 µF
GND
OUT VO (–VI)
1
IO
IN
0.4 V
25 mA
CO
1 µF
GND
4
0.4 V 1.25 V
Figure 30. Typical Load
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
shutting down the TPS6040x
If shutdown is necessary, use the circuit in Figure 32. The output resistance of the TPS6040x will typically be
15 Ω plus two times the output resistance of the buffer.
Connecting multiple buffers in parallel can reduce the output resistance of the buffer driving the IN pin.
VI
C(fly)
1
2
SDN
3
VO (–VI)
1 µF
OUT
C1+
TPS60400
IN
C1–
GND
5
CO
1 µF
4
CI
1 µF
GND
GND
Figure 32. Shutdown Control
GaAs supply
A solution for a –2.7-V/3-mA GaAs bias supply is proposed in Figure 33. The input voltage of 3.3 V is first inverted
with a TPS60403 and stabilized using a TLV431 low-voltage shunt regulator. Resistor RP with capacitor CP is
used for filtering the output voltage.
RP
VI (3.3 V)
C(fly)
VO (–2.7 V/3 mA)
0.1 µF
R2
1
2
3
OUT
C1+
TPS60400
IN
C1–
GND
5
CO
1 µF
CP
TLV431
R1
4
CI
0.1 µF
GND
GND
Figure 33. GaAs Supply
ǒ
V O + * 1 ) R1
R2
Ǔ
V ref * R1
I
I(ref)
A 0.1-µF capacitor was selected for C(fly). By this, the output resistance of the inverter is about 52 Ω.
18
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UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
GaAs supply (continued)
RPMAX can be calculated using the following equation:
R PMAX +
ǒ
V CO * V O
IO
* RO
Ǔ
With: VCO = –3.3 V; VO = –2.7 V; IO = –3 mA
RPMAX = 200 Ω – 52 Ω = 148 Ω
A 100-Ω resistor was selected for RP.
The reference voltage across R2 is 1.24 V typical. With 5-µA current for the voltage divider, R2 gets:
R2 + 1.24 V [ 250 kW
5 mA
R1 + 2.7 * 1.24 V [ 300 kW
5 mA
With CP = 1 µF the ratio VO/VI of the RC post filter is:
Ť Ť
VO
VI
+
1
Ǹ1 ) (2p125000Hz
100W
1 mF)
2
[ 0.01
step-down charge pump
By exchanging GND with OUT (connecting the GND pin with OUT and the OUT pin with GND), a step-down
charge pump can easily be formed. In the first cycle S1 and S3 are closed, and C(fly) with CO in series are
charged. Assuming the same capacitance, the voltage across C(fly) and CO is split equally between the
capacitors. In the second cycle, S2 and S4 close and both capacitors with VI/2 across are connected in parallel.
VI
C(fly)
VI
S1
1
C(fly)
+
S4
GND
2
1 µF
S2
CO
1 µF
S3
VO (VI/2)
VO (VI/2)
Figure 34. Step-Down Principle
3
CI
1 µF
GND
1 µF
OUT
C1+
TPS60400
IN
C1–
GND
5
4
VO (VI/2)
CO
1 µF
GND
Figure 35. Step-Down Charge Pump Connection
The maximum input voltage between VI and GND in the schematic (or between IN and OUT at the device itself)
must not exceed 6.5 V. For input voltages in the range of 6.5 V to 11 V, an additional Zener-diode is
recommended (see Figure 36).
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
5V6
VI
C(fly)
1 µF
1 OUT
2
3
C1+ 5
TPS60400
IN
C1–
GND
4
CI
1 µF
VO – VI
CO
1 µF
GND
GND
Figure 36.
power dissipation
As given in the data sheet, the thermal resistance of the unsoldered package is RθJA = 347°C/W. Soldered on
the EVM, a typical thermal resistance of RθJA(EVM) = 180°C/W was measured.
The terminal resistance can be calculated using the following equation:
R
T *T
A
+ J
qJA
P
D
Where:
TJ is the junction temperature.
TA is the ambient temperature.
PD is the power that needs to be dissipated by the device.
R
T *T
A
+ J
qJA
P
D
The maximum power dissipation can be calculated using the following equation:
PD = VI × II – VO × IO = VI(max) × (IO + I(SUPPLY)) – VO × IO
The maximum power dissipation happens with maximum input voltage and maximum output current.
At maximum load the supply current is 0.7 mA maximum.
PD = 5 V × (60 mA + 0.7 mA) – 4.4 V × 60 mA = 40 mW
With this maximum rating and the thermal resistance of the device on the EVM, the maximum temperature rise
above ambient temperature can be calculated using the following equation:
∆TJ = RθJA × PD = 180°C/W × 40 mW = 7.2°C
This means that the internal dissipation increases TJ by <10°C.
The junction temperature of the device shall not exceed 125°C.
This means the IC can easily be used at ambient temperatures up to:
TA = TJ(max) – ∆TJ = 125°C/W – 10°C = 115°C
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
APPLICATION INFORMATION
layout and board space
All capacitors should be soldered as close as possible to the IC. A PCB layout proposal for a single-layer board
is shown in Figure 37. Care has been taken to connect all capacitors as close as possible to the circuit to achieve
optimized output voltage ripple performance.
CFLY
IN
CIN
COUT
OUT
GND
U1
TPS60400
Figure 37. Recommended PCB Layout for TPS6040x (top layer)
device family products
Other inverting dc-dc converters from Texas Instruments are listed in Table 5.
Table 5. Product Identification
PART NUMBER
DESCRIPTION
TPS6735
Fixed negative 5-V, 200-mA inverting dc-dc converter
TPS6755
Adjustable 1-W inverting dc-dc converter
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TPS60400, TPS60401, TPS60402, TPS60403
UNREGULATED 60-mA CHARGE PUMP VOLTAGE INVERTER
SLVS324 – JULY 2001
MECHANICAL DATA
DBV (R-PDSO-G5)
PLASTIC SMALL-OUTLINE
0,50
0,30
0,95
5
0,20 M
4
1,70
1,50
1
0,15 NOM
3,00
2,60
3
Gage Plane
3,00
2,80
0,25
0°–8°
0,55
0,35
Seating Plane
1,45
0,95
0,05 MIN
0,10
4073253-4/F 10/00
NOTES: A.
B.
C.
D.
22
All linear dimensions are in millimeters.
This drawing is subject to change without notice.
Body dimensions do not include mold flash or protrusion.
Falls within JEDEC MO-178
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