TI PT6984A

PT6980 Series
10-A 12V-Input Dual Output
Integrated Switching Regulator
SLTS154
Revised (10/2/2001)
Features
• Dual Outputs
• Soft-Start
• Internal Sequencing
• Short Circuit Protection
• 23-pin Space-Saving Package
• Solderable Copper Case
(See Ordering Information)
•
•
•
•
•
Ideal Power Source for DSPs
12V Input
Outputs Adjustable
Remote Sensing (Vo1 & Vo2)
Standby Function
Pin-Out Information
Description
Ordering Information
The PT6980 Excalibur™ series of
power modules are dual output integrated
switching regulators (ISRs) specifically
designed to power mixed signal ICs.
Operating from a 12-V input bus, the dual
output provides power for both the digital
I/O logic and a DSP core from a single
module. Both output voltages are internally
sequenced during power-up and powerdown to comply with the requirements of
the latest DSP chips. Each output is independently adjustable or can be set to at
least one alternative bus voltage with a
simple pin-strap. The modules are made
available in a space-saving solderable case.
The features include output current limit
and short-circuit protection.
PT6981o = +2.5/1.8 Volts
PT6982o = +3.3/2.5 Volts
PT6983o = +3.3/1.8 Volts
PT6984o = +3.3/1.2 Volts
PT6985o = +2.5/1.2 Volts
Pin Function
Pin
Function
1
Vo1 Sense
13
Vo1
2
No Connect
14
Vo1
3
STBY
15
Vo1
4
Vin
16
Vo1 Adjust *
5
Vin
17
No Connect
6
Vin
18
Vo2
PT Series Suffix (PT1234x)
7
GND
19
Vo2
Case/Pin
Configuration
Order
Suffix
Package
Code
8
GND
20
Vo2
9
GND
21
Vo2
N
A
C
(ELF)
(ELG)
(ELH)
10
GND
22
Vo2 Sense
11
GND
23
Vo2 Adjust *
12
Vo1
Vertical
Horizontal
SMD
(Reference the applicable package code drawing
for the dimensions and PC layout)
* Vo1 and Vo2 can be pin-strapped to another voltage.
See application note on output voltage adjustment.
Standard Application
V o 2 Sense
STBY
V o 1 Sense
3
22
1
18-21
V IN
4,5,6
Vo 2
PT6980
12-15
Vo 1
+
7-11
C1
16
23
+
C3
C2
GND
GND
C1 = Req’d 560µF electrolytic
C2 = Req’d 330µF electrolytic
C3 = Optional 100µF electrolytic
For technical support and more information, see inside back cover or visit www.ti.com
PT6980 Series
10-A 12V-Input Dual Output
Integrated Switching Regulator
General Specifications
(Unless otherwise stated, Ta =25°C, Vin =12V)
Characteristic
Symbol
Short Circuit Current
Switching Frequency
Standby (Pin 3)
Input High Voltage
Input Low Voltage
Input Low Current
Standby Input Current
External Output Capacitance
Isc
ƒo
Maximum Operating
Temperature Range
Storage Temperature
Mechanical Shock
VIH
V IL
IIL
Iin standby
C2
C3
Ta
Ts
Mechanical Vibration
Weight
Flammability
—
—
Conditions
Min
Io1 + Io2 combined
Over Vin range
Referenced to GND (pin 7)
pin 3 to GND
Over Vin Range
—
Per Mil-STD-883D, Method 2002.3
1 msec, ½ Sine, mounted
Per Mil-STD-883D, Method 2007.2
20-2000 Hz, Soldered in a PC board
Vertical/Horizontal
Meets UL 94V-O
PT6980 Series
Typ
Max
Units
—
500
19
550
—
600
A
kHz
—
–0.1
—
—
330 (2)
0
–40 (3)
—
—
-0.5
4
—
—
—
Open (1)
+0.4
–
6
15,000 (2)
330
+85 (4)
–40
—
+125
°C
—
500
—
G ’s
—
—
15
26
—
—
G ’s
grams
V
mA
mA
µF
°C
Notes: (1) The Standby (pin 3) has an internal pull-up to Vin, and if it is left open circuit the module will operate when input power is applied.Refer to the application
notes for interface considerations.
(2) The total combined ESR of all output capacitance at 100kHz must be (less than) <50 mΩ.
(3) For operating temperatures below 0°C, Cin and Cout must have stable characteristics. Use either tantalum or Oscon® capacitors.
(4) See Safe Operating Area curves for the specific output voltage combination, or contact the factory for the appropriate derating.
Input/Output Capacitors: The PT6980 series requires a 330µF electrolytic capacitor at both the input and output for proper operation (300µF for Oscon® or low ESR
tantalum). In addition, the input capacitance must be rated for a minimum of 1.0Arms ripple current. For transient or dynamic load applications, additional capacitance
may be required. Refer to the application notes for more information.
Power-up Sequencing and Vo1/Vo2 Loading
Power-up Sequencing
The PT6980 series of regulators provide two output voltages,
Vo1 and Vo 2. Each of the output voltage combinations
offered by the PT6980 series provides power for both a lowvoltage processor core, and the associated digital support
circuitry. In addition, each output is internally sequenced
during power-up and power-down to comply with the
requirements of most DSP and µP IC’s, and their accompanying chipsets. Figure 1 shows the typical waveforms of the
output voltages, Vo1 and Vo2, from the instance that either
input power is applied or the module is enabled via the
Standby pin. Following a delay of about 25 milli-secs, the
voltages at Vo1 and Vo2 rise together until Vo2 reaches its
set-point. Then Vo1 continues to rise until both output
voltages have reached full voltage.
Figure 1; PT6980 Series Power-up
V1 (1V/Div)
V2 (1V/Div)
Vstby (10V/Div)
Vo1/Vo2 Loading
The output voltages from the PT6980 series regulators are
independently regulated. The voltage at Vo1 is produced
by a highly efficient switching regulator. The lower output
voltage, Vo2, is derived from Vo1. The regulation method
used for Vo 2 also provides control of this output voltage
during power-down. Vo2 will sink current if the voltage at
Vo1 attempts to fall below it.
The load specifications for each model of the PT6980
series gives both a ‘Typical’ (Typ) and ‘Maximum’ (Max)
load current for each output. For operation within the
product’s rating, the load currents at Vo1 and Vo2 must
comply with the following limits:• Io 2 must be less than Io2(max).
• The sum-total current from both outputs (Io1 + Io2)
must not exceed Io1(max).
In the case that either Vo1 or Vo2 are adjusted to some
other value than the default output voltage, the absolute
maximum load current for Io2 must be revised to comply
with the following equation.
Io2 (max)
=
2.5
Vo1 – Vo2
Adc
Consult the specification table for each model of the series
for the actual numeric values.
HORIZ SCALE: 5ms/Div
For technical support and more information, see inside back cover or visit www.ti.com
PT6981
10.5-A 12V-Input Dual Output
Integrated Switching Regulator
PT6981 Performance Specifications
(Unless otherwise stated, T a =25°C, Vin =12V, C1 =560µF, C 2 =330µF, Io1 =Io1typ, and Io2 =Io 2typ)
Characteristic
Symbol
Conditions
Output Current
Ta =25°C, natural convection
Input Voltage Range
Set Point Voltage Tolerance
Io1
Io2
Io1
Io2
Vin
Vo tol
Temperature Variation
Regtemp
–40° >Ta > +85°C
Line Regulation
Regline
Over Vin range
Load Regulation
Regload
Over Io range
Total Output Voltage Variation
∆Votot
Includes set-point, line, load
–40° >Ta > +85°C
Efficiency
Vo Ripple (pk-pk)
η
Vr
Transient Response
ttr
Vo1 (2.5V)
Vo2 (1.8V)
Vo1 (2.5V)
Vo2 (1.8V)
Ta =60°C, 200LFM airflow
0.1
0
0.1
0
10.8
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Over Io Range
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
20MHz bandwidth
Vo1
Vo2
1A/µs load step, 50% to 100% Iotyp
Vo over/undershoot
∆Vtr
PT6981 (2.5V/1.8V)
Typ
Max
Min
Vo1
Vo2
8 (ii)
2.5 (ii)
8 (ii)
2.5 (ii)
—
±12
±9
±0.5
±0.5
±10
±5
±10
±5
±44
±28
80
35
35
60
±50
±20
(i)
(i)
Units
10.5 (iii)
2.5 (iii)
10.5 (iii)
2.5 (iii)
13.2
±38
±27
—
—
±15
±7
±15
±7
—
—
—
—
—
—
—
—
A
A
VDC
mV
%Vo
mV
mV
mV
%
mVpp
µs
mV
Notes: (i) Io1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications.
(ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions.
(iii) The sum of Io1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max.
PT6981 Typical Characteristics
Efficiency vs Io1 (See Note A)
Power Dissipation vs Io 1 (See Note A)
7
90
85
6
Io2 (A)
Io2 (A)
0.5
1
1.5
2
2.5
75
70
65
5
Pd - Watts
Efficiency - %
80
2.5
2
1.5
1
0.5
0.1
4
3
2
60
1
55
50
0
0
1
2
3
4
5
6
7
0
8
1
2
3
Io1 (A)
Vo1 Output Ripple vs Io1 (See Note A)
5
6
7
60
80
Ambient Temperature (°C)
90
40
30
20
10
Airflow
70
200LFM
120LFM
60LFM
Nat conv
60
50
40
30
0
20
0
1
2
3
8
Safe Operating Area, V in =12V (See Note B)
70
50
Ripple - mV
4
Io1 (A)
4
5
6
7
8
0
Io1 (A) [ Io2 fixed at Io2(typ) ]
1
2
3
4
5
6
Io1 (A) [ Io2 fixed at Io2(typ) ]
Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter.
Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures
For technical support and more information, see inside back cover or visit www.ti.com
7
8
PT6982
10.5-A 12V-Input Dual Output
Integrated Switching Regulator
PT6982 Performance Specifications
(Unless otherwise stated, T a =25°C, Vin =12V, C1 =560µF, C 2 =330µF, Io 1 =Io1typ, and Io2 =Io 2typ)
Characteristic
Symbol
Conditions
Output Current
Ta =25°C, natural convection
Input Voltage Range
Set Point Voltage Tolerance
Io1
Io2
Io1
Io2
Vin
Vo tol
Temperature Variation
Regtemp
–40° >Ta > +85°C
Line Regulation
Regline
Over Vin range
Load Regulation
Regload
Over Io range
Total Output Voltage Variation
∆Votot
Includes set-point, line, load
–40° >Ta > +85°C
Efficiency
Vo Ripple (pk-pk)
η
Vr
Transient Response
ttr
Min
Vo1 (3.3V)
Vo2 (2.5V)
Vo1 (3.3V)
Vo2 (2.5V)
Ta =60°C, 200LFM airflow
0.1 (i)
0
0.1 (i)
0
10.8
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Over Io Range
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
20MHz bandwidth
Vo1
Vo2
1A/µs load step, 50% to 100% Iotyp
Vo over/undershoot
∆Vtr
PT6982 (3.3V/2.5V)
Typ
Max
Vo1
Vo2
8.5 (ii)
2 (ii)
8.5 (ii)
2 (ii)
—
±16
±12
±1.0
±0.5
±10
±5
±10
±10
±69
±39
84
35
35
60
±50
±30
Units
10.5 (iii)
2.25 (iii)
10.5 (iii)
2.25 (iii)
13.2
±50
±38
—
—
±15
±7
±15
±13
—
—
—
—
—
—
—
—
A
A
VDC
mV
%Vo
mV
mV
mV
%
mVpp
µs
mV
Notes: (i) Io 1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications.
(ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions.
(iii) The sum of Io 1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max.
PT6982 Typical Characteristics
Efficiency vs Io1 (See Note A)
Power Dissipation vs Io 1 (See Note A)
90
7
85
6
5
Io2 (A)
75
1
1.5
2
70
65
Pd - Watts
Efficiency - %
80
Io2 (A)
2
1.5
1
0.1
4
3
2
60
1
55
50
0
0
1
2
3
4
5
6
7
8
0
1
2
3
4
Io1 (A)
Vo1 Output Ripple vs Io 1 (See Note A)
6
7
8
Safe Operating Area, V in =12V (See Note B)
90
60
80
Ambient Temperature (°C)
70
50
Ripple - mV
5
Io1 (A)
40
30
20
70
Airflow
200LFM
120LFM
60LFM
Nat conv
60
50
40
30
10
20
0
0
1
2
3
4
5
6
Io1 (A) [ Io2 fixed at Io2(typ) ]
7
8
0
1
2
3
4
5
6
7
8
Io1 (A) [ Io2 fixed at Io2(typ) ]
Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter.
Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures
For technical support and more information, see inside back cover or visit www.ti.com
PT6983
9.5-A 12V-Input Dual Output
Integrated Switching Regulator
PT6983 Performance Specifications
(Unless otherwise stated, T a =25°C, Vin =12V, C1 =560µF, C 2 =330µF, Io1 =Io1typ, and Io2 =Io 2typ)
Characteristic
Symbol
Conditions
Output Current
Ta =25°C, natural convection
Input Voltage Range
Set Point Voltage Tolerance
Io1
Io2
Io1
Io2
Vin
Vo tol
Temperature Variation
Regtemp
–40° >Ta > +85°C
Line Regulation
Regline
Over Vin range
Load Regulation
Regload
Over Io range
Total Output Voltage Variation
∆Votot
Includes set-point, line, load
–40° >Ta > +85°C
Efficiency
Vo Ripple (pk-pk)
η
Vr
Transient Response
ttr
Vo1 (3.3V)
Vo2 (1.8V)
Vo1 (3.3V)
Vo2 (1.8V)
Ta =60°C, 200LFM airflow
0.1 (i)
0
0.1 (i)
0
10.8
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Over Io Range
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
20MHz bandwidth
Vo1
Vo2
1A/µs load step, 50% to 100% Iotyp
Vo over/undershoot
∆Vtr
PT6983 (3.3V/1.8V)
Typ
Max
Min
Vo1
Vo2
7.5 (ii)
2 (ii)
7.5 (ii)
2 (ii)
—
±16
±9
±1.0
±0.5
±10
±5
±10
±5
±69
±28
81
35
35
60
±50
±20
Units
9.5 (iii)
2 (iii)
9.5 (iii)
2 (iii)
13.2
±50
±27
—
—
±15
±7
±15
±7
—
—
—
—
—
—
—
—
A
A
VDC
mV
%Vo
mV
mV
mV
%
mVpp
µs
mV
Notes: (i) Io1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications.
(ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions.
(iii) The sum of Io1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max.
PT6983 Typical Characteristics
Efficiency vs Io1 (See Note A)
Power Dissipation vs Io 1 (See Note A)
90
8
85
7
6
Io2 (A)
Io2 (A)
75
1
1.5
2
70
65
Pd - Watts
Efficiency - %
80
5
2
1.5
1
0.1
4
3
60
2
55
1
0
50
0
1
2
3
4
5
6
0
7
1
2
3
Vo1 Output Ripple vs Io1 (See Note A)
5
6
7
Safe Operating Area, V in =12V (See Note B)
90
60
80
Ambient Temperature (°C)
70
50
Ripple - mV
4
Io1 (A)
Io1 (A)
40
30
20
10
Airflow
70
200LFM
120LFM
60LFM
Nat conv
60
50
40
30
0
20
0
1
2
3
4
5
6
7
0
Io1 (A) [ Io2 fixed at Io2(typ) ]
1
2
3
4
5
6
Io1 (A) [ Io2 fixed at Io2(typ) ]
Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter.
Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures
For technical support and more information, see inside back cover or visit www.ti.com
7
PT6984
8.6-A 12V-Input Dual Output
Integrated Switching Regulator
PT6984 Performance Specifications
(Unless otherwise stated, T a =25°C, Vin =12V, C1 =560µF, C 2 =330µF, Io 1 =Io1typ, and Io2 =Io 2typ)
Characteristic
Symbol
Conditions
Output Current
Ta =25°C, natural convection
Input Voltage Range
Set Point Voltage Tolerance
Io1
Io2
Io1
Io2
Vin
Vo tol
Temperature Variation
Regtemp
–40° >Ta > +85°C
Line Regulation
Regline
Over Vin range
Load Regulation
Regload
Over Io range
Total Output Voltage Variation
∆Votot
Includes set-point, line, load
–40° >Ta > +85°C
Efficiency
Vo Ripple (pk-pk)
η
Vr
Transient Response
ttr
Vo1 (3.3V)
Vo2 (1.2V)
Vo1 (3.3V)
Vo2 (1.2V)
Ta =60°C, 200LFM airflow
0.1 (i)
0
0.1 (i)
0
10.8
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Over Io Range
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
20MHz bandwidth
Vo1
Vo2
1A/µs load step, 50% to 100% Iotyp
Vo over/undershoot
∆Vtr
PT6984 (3.3V/1.2V)
Typ
Max
Min
Vo1
Vo2
7 (ii)
1.6 (ii)
7 (ii)
1.6 (ii)
—
±16
±6
±1.0
±0.5
±10
±5
±10
±5
±69
±22
78
35
35
60
±50
±20
Units
8.6 (iii)
1.6 (iii)
8.6 (iii)
1.6 (iii)
13.2
±50
±18
—
—
±15
±7
±15
±7
—
—
—
—
—
—
—
—
A
A
VDC
mV
%Vo
mV
mV
mV
%
mVpp
µs
mV
Notes: (i) Io 1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications.
(ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions.
(iii) The sum of Io 1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max.
PT6984 Typical Characteristics
Efficiency vs Io1 (See Note A)
Power Dissipation vs Io 1 (See Note A)
90
8
85
7
0.5
0.75
1
1.25
1.6
75
70
65
Io2 (A)
6
Io2 (A)
Pd - Watts
Efficiency - %
80
4
3
60
2
55
1
50
1.6
1.25
1.0
0.75
0.5
0.1
5
0
0
1
2
3
4
5
6
7
0
1
2
3
Io1 (A)
Vo1 Output Ripple vs Io 1 (See Note A)
5
6
7
Safe Operating Area, V in =12V (See Note B)
90
60
80
Ambient Temperature (°C)
70
50
Ripple - mV
4
Io1 (A)
40
30
20
Airflow
70
200LFM
120LFM
60LFM
Nat conv
60
50
40
30
10
20
0
0
1
2
3
4
Io1 (A) [ Io2 fixed at Io2(typ) ]
5
6
7
0
1
2
3
4
5
6
7
Io1 (A) [ Io2 fixed at Io2(typ) ]
Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter.
Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures
For technical support and more information, see inside back cover or visit www.ti.com
PT6985
9-A 12V-Input Dual Output
Integrated Switching Regulator
PT6985 Performance Specifications
(Unless otherwise stated, T a =25°C, Vin =12V, C1 =560µF, C 2 =330µF, Io1 =Io1typ, and Io2 =Io 2typ)
Characteristic
Symbol
Conditions
Output Current
Ta =25°C, natural convection
Input Voltage Range
Set Point Voltage Tolerance
Io1
Io2
Io1
Io2
Vin
Vo tol
Temperature Variation
Regtemp
–40° >Ta > +85°C
Line Regulation
Regline
Over Vin range
Load Regulation
Regload
Over Io range
Total Output Voltage Variation
∆Votot
Includes set-point, line, load
–40° >Ta > +85°C
Efficiency
Vo Ripple (pk-pk)
η
Vr
Transient Response
ttr
Vo1 (2.5V)
Vo2 (1.2V)
Vo1 (2.5V)
Vo2 (1.2V)
Ta =60°C, 200LFM airflow
0.1 (i)
0
0.1 (i)
0
10.8
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Over Io Range
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
Vo1
Vo2
20MHz bandwidth
Vo1
Vo2
1A/µs load step, 50% to 100% Iotyp
Vo over/undershoot
∆Vtr
PT6985 (2.5V/1.2V)
Typ
Max
Min
Vo1
Vo2
7 (ii)
2 (ii)
7 (ii)
2 (ii)
—
±12
±6
±0.5
±0.5
±10
±5
±10
±5
±44
±22
77
35
35
60
±50
±20
Units
9 (iii)
2.2 (iii)
9 (iii)
2.2 (iii)
13.2
±38
±18
—
—
±15
±7
±15
±7
—
—
—
—
—
—
—
—
A
A
VDC
mV
%Vo
mV
mV
mV
%
mVpp
µs
mV
Notes: (i) Io1(min) current of 0.1A can be divided between both outputs, Vo1 or Vo2. The module will operate at no load with reduced specifications.
(ii) The typical current is that which can be drawn simultaneously from both outputs under the stated operating conditions.
(iii) The sum of Io1 and Io2 must be less than Io1max, and Io 2 must be less than Io2max.
PT6985 Typical Characteristics
Efficiency vs Io1 (See Note A)
Power Dissipation vs Io 1 (See Note A)
90
7
85
6
5
Io2 (A)
75
1
1.5
2
70
65
Pd - Watts
Efficiency - %
80
Io2 (A)
2
1.5
1
0.1
4
3
2
60
1
55
50
0
0
1
2
3
4
5
6
0
7
1
2
3
Io1 (A)
Vo1 Output Ripple vs Io1 (See Note A)
5
6
7
Safe Operating Area, V in =12V (See Note B)
90
30
80
Ambient Temperature (°C)
25
20
Ripple - mV
4
Io1 (A)
15
10
5
Airflow
70
200LFM
120LFM
60LFM
Nat conv
60
50
40
30
20
0
0
1
2
3
4
5
6
7
0
Io1 (A) [ Io2 fixed at Io2(typ) ]
1
2
3
4
5
Io1 (A) [ Io2 fixed at Io2(typ) ]
Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter.
Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures
For technical support and more information, see inside back cover or visit www.ti.com
6
7
Application Notes
PT6980 Series
Capacitor Recommendations for the
Dual-Output PT6980 Regulator Series
Input Capacitors:
The recommended input capacitance is determined by 1.0
ampere minimum ripple current rating and 330µF minimum
capacitance . Ripple current and <100mΩ equivalent series resistance (ESR) values are the major considerations,
along with temperature, when designing with different
types of capacitors. Tantalum capacitors have a recommended
minimum voltage rating of 2 × the maximum DC voltage +
AC ripple. This is necessary to insure reliability for input
voltage bus applications
Output Capacitors: C2(Required), C3(Optional)
The ESR of the required capacitor (C2) must not be greater
than 50mΩ. Electrolytic capacitors have poor ripple performance at frequencies greater than 400kHz but excellent
low frequency transient response. Above the ripple frequency, ceramic capacitors are necessary to improve the
transient response and reduce any high frequency noise
components apparent during higher current excursions.
Preferred low ESR type capacitor part numbers are identified
in Table 1. The optional 100µF capacitor (C3) for V2out can
have an ESR of up to 200mΩ for optimum performance
and ripple reduction. (Note: Vendor part numbers for the
optional capacitor, C3, are not identified in the table. Use the
same series selected for C2)
Tantalum Capacitors
Tantalum type capacitors may be used at the output, but
only the AVX TPS series, Sprague 593D/594/595 series,
or Kemet T495/T510 series. The AVX TPS series, Kemet
or Sprague series tantalums are recommended over many
other types due to their higher rated surge, power dissipation,
and ripple current capability. As a caution, the TAJ series
by AVX is not recommended. This series has considerably
higher ESR, reduced power dissipation and lower ripple
current capability. The TAJ Series is also less reliable than
the AVX TPS series when determining power dissipation
capability. Tantalum or Oscon® types are recommended
for applications where ambient temperatures fall below 0°C.
Capacitor Table
Table 1 identifies the characteristics of capacitors from a
number of vendors with acceptable ESR and ripple current
(rms) ratings. The number of capacitors required at both the
input and output buses is identified for each capacitor type.
This is not an extensive capacitor list. Capacitors from other
vendors are available with comparable specifications. Those listed
are for guidance. The RMS ripple current rating and ESR
(Equivalent Series Resistance at 100kHz) are critical parameters
necessary to insure both optimum regulator performance and
long capacitor life.
Table 1: Input/Output Capacitors
Capacitor
Vendor/
Component
Series
Capacitor Characteristics
Quantity
Working
Voltage
Value(µF)
(ESR) Equivalent
Series Resistance
85°C Maximum Ripple
Current(Irms)
Physical
Size(mm)
Input
Bus
Output
Bus
Vendor Number
Panasonic
FC
35V
35V
50V
680µF
560µF
680µF
0.043Ω
0.038Ω
0.048Ω
1690mA
1655mA
1835mA
16x15
12.5x20
16x20
1
1
1
1
1
1
EEUFC1V681S
EEUFC1V561S
EEUFC1H681
Un ited
Chemi-con
LXV/LXZ/
FX/FS
35V
50V
10V
20V
680µF
680µF
390µF
150µF
0.038Ω
0.048Ω
0.030Ω
0.024Ω
1660mA
1840mA
3080mA
3200mA
12.5x20
16x20
8x10.5
8x10.5
1
1
N/R
4
1
1
1
2
LXZ35VB681M112X20LL
LXZ50VB681M16X20LL
10FX390M
20FX150M
Nichicon
PL/
PM
35V
25V
35V
560µF
820µF
560µF
0.048Ω
0.049Ω
0.0048Ω
1360mA
1340mA
1360mA
16x15
16x15
16x15
1
1
1
1
1
1
UPL1V561MHH6
UPL1E821MHH6
UPM1V561MHH6
Panasonic
FC
Surface Mtg
35V
35V
35V
330µF
1000µF
470µF
0.065÷2Ω
0.038Ω
0.043Ω
>1205mA
2000mA
1690mA
12.5x16.5
18x16.5
16x16.5
2
1
2
1
1
EEVFC1V331LQ
EEVFC1V1021N
EEVFC1V471N
10V
10V
330µF
330µF
0.025Ω
0.025Ω
>3500mA
>3800mA
10.0x10.5
10.3x10.3
N/R
N/R
1
1
10SS330M
10SV330M
Surface Mount(SV)
10V
10V
330µF
220µF
0.060÷2Ω
0.060÷2Ω
>2500mA
>3000mA
7.3Lx
4.3Wx
N/R
N/R
2
2
TPSV337M010R0060
TPSV227M010R0060
10V
10V
330µF
220µF
0.033Ω
0.07Ω÷2 =0.035Ω
1400mA
>2000mA
7.3Lx5.7W
x 4.0H
N/R
N/R
1
2
T510X337M010AS
T495X227M010AS
10V
330µF
0.045Ω
2350mA
N/R
1
594D337X0010R2T
Oscon SS/SV
AVX
Tantalum
TPS
Kemet
T510
T495
Sprague
594D
7.3Lx
6.0Wx
4.1H
N/R –Not recommended. The voltage rating does not meet the minimin operating limits.
For technical support and more information, see inside back cover or visit www.ti.com
Application Notes
PT6980 Series
Adjusting the Output Voltage of the PT6980
Dual-Output Voltage Regulators
Each output voltage from the PT6980 series of integrated
switching regulators (ISRs) can be independently adjusted
higher or lower than the factory trimmed pre-set voltage.
The voltages, Vo1 and Vo2 may be adjusted either up or
down using a single external resistor 1. Table 1 gives the
adjustment range for both Vo1 and Vo2 for each model in
the series as Va(min) and Va(max). Note that Vo2 must
always be lower than Vo1 2.
Vo1 Adjust Up: To increase the output, add a resistor R4
between pin 16 (V1 Adjust) and pins 7-11 (GND) 1.
Vo1 Adjust Down: Add a resistor (R3), between pin 16
(Vo1 Adjust) and pin 1 (Vo1 Sense) 1.
3. Both the Vo1 and Vo2 may be adjusted down to an
alternative bus voltage by making, (R3) or (R1)
respectively, a zero ohm link. Refer to the Table 1
footnotes for guidance.
4. Never connect capacitors to either the Vo1 Adjust or
Vo2 Adjust pins. Any capacitance added to these control
pins will affect the stability of the respective regulated
output.
5. Adjusting either voltage (Vo1 or Vo2) may increase the
power dissipation in the regulator, and change the
maximum current available at either output. Consult
the note on p.2 of the data sheet regarding Vo1/Vo2
loading.
The adjust up and adjust down resistor values can also be
calculated using the following formulas. Be sure to select
the correct formula parameter from Table 1 for the output
and model being adjusted.
Vo2 Adjust Up: Add a resistor R2 between pin 23
(Vo2 Adjust) and pins 7-11 (GND) 1.
Vo2 Adjust Down: Add a resistor (R1) between pin 23
(Vo2 Adjust) and pin 22 (Vo2 Sense) 1.
Refer to Figure 1 and Table 2 for both the placement and value of
the required resistor.
Notes:
1. Use only a single 1% resistor in either the (R3) or R4
location to adjust Vo1, and in the (R1) or R2 location to
adjust Vo2. Place the resistor as close to the ISR as
possible.
2. Vo2 must always be at least 0.2V lower than Vo1.
10 (Va – Vr )
Vo – Va
– Rs
kΩ
– Rs
kΩ
(R1) or (R3)
=
(R2) or (R4)
=
Where: Vo
Va
Vr
Rs
= Original output voltage, (Vo1 or Vo2)
= Adjusted output voltage
= The reference voltage from Table 1
= The series resistance from Table 1
10 · Vr
Va – Vo
Figure 1
22
1
Vo 2 (sns) Vo 1 (sns)
Vo 2
4,5,6
V IN
Vo 1
STBY
3
+
18 - 21
Vo 2
12 - 15
Vo 1
PT6980
Vin
GND
7 - 11
Vo 2 (adj) Vo 1 (adj)
23
16
(R3)
Adj Down
(R1)
C1
+
C2
R4
Adjust Up
+
C3
L
O
A
D
L
O
A
D
R2
COM
COM
Adjust Vo 1
For technical support and more information, see inside back cover or visit www.ti.com
Adjust Vo 2
Application Notes
PT6980 Series
Table 1
ADJUSTMENT RANGE AND FORMULA PARAMETERS
Vo1 Bus
Series Pt #
Adj. Resistor
Vo(nom)
Va(min)
Va(max)
Vr
Ω)
Rs (kΩ
Ref. Note 3:
PT6981/85
(R3)/R4
PT6982/83/84
(R3)/R4
Vo2 Bus (2)
PT6984/85
(R1)/R2
PT6981/83
(R1)/R2
PT6936
(R1)/R2
2.5V
1.8V *
3.6V
1.27V
7.5
3.3V
2.5V *
3.6V
1.27V
15.4
1.2V
1.0V †
1.5V #
0.6125V
20.0
1.8V
1.5V †
2.4V
1.0V
16.9
2.5V
1.8V †
3.0
1.0V
11.5
Vo2 Bus
Series Pt #
Adj. Resistor
PT6984/85
(R1)/R2
PT6981/83
(R1)/R2
1.2V
1.8V
* (R3) = Zero-ohm link
†(R1) = Zero-ohm link
# (R2) = Zero-ohm link
Table 2
ADJUSTMENT RESISTOR VALUES
Vo1 Bus
Series Pt #
Adj. Resistor
Vo(nom)
Va(req’d)
1.8
1.85
1.9
1.95
2.0
2.05
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
3.1
3.2
3.3
3.4
3.5
3.6
PT6981/85
(R3)/R4
PT6982/83/84
(R3)/R4
2.5V
3.3V
(0.0)
(1.4)kΩ
(3.0)kΩ
(4.9)kΩ
(7.1)kΩ
(9.8)kΩ
(13.3)kΩ
(23.5)kΩ
(44.0)kΩ
(106.0)kΩ
120.0kΩ
56.0kΩ
34.8kΩ
24.3kΩ
17.9kΩ
13.7kΩ
10.6kΩ
8.4kΩ
6.6kΩ
5.2kΩ
4.1kΩ
(0.0)kΩ
(3.6)kΩ
(8.4)kΩ
(15.2)kΩ
(25.4)kΩ
(42.3)kΩ
(76.1)kΩ
(178.0)kΩ
112.0k
48.1k
26.9k
Vo(nom)
Va(req’d)
1.0
1.05
1.1
1.15
1.2
1.25
1.3
1.35
1.4
1.45
1.5
1.55
1.6
1.65
1.7
1.75
1.8
1.85
1.9
1.95
2.0
2.05
2.1
2.2
2.3
2.4
2.5
2.6
2.7
2.8
2.9
3.0
PT6982
(R1)/R2
2.5V
(0.0)kΩ
(9.2)kΩ
(28.8)kΩ
(87.5)kΩ
101.5kΩ
41.2kΩ
20.8kΩ
10.6kΩ
4.5kΩ
0.0kΩ
(0.0)kΩ
(5.1)kΩ
(13.1)kΩ
(26.4)kΩ
(53.1)kΩ
(133.0)kΩ
183.0kΩ
83.1kΩ
49.8kΩ
33.1kΩ
23.1kΩ
16.4kΩ
8.1kΩ
3.1kΩ
0.0kΩ
(0.0)kΩ
(1.6)kΩ
(3.5)kΩ
(5.8)kΩ
(8.5)kΩ
(11.8)kΩ
(16.0)kΩ
(28.5)kΩ
(53.5)kΩ
(129.0)kΩ
88.5kΩ
38.5kΩ
21.8kΩ
13.5kΩ
8.5kΩ
R1/R3 = (Blue), R2/R4 = Black
For technical support and more information, see inside back cover or visit www.ti.com
Application Notes
PT6980 Series
Using the Standby Function on the PT6980
Series of Dual-Output Voltage Regulators
Both output voltages of the 23-pin PT6980 dual-output
converter may be disabled using the regulator’s ‘Standby’
function. This function may be used in applications that
require power-up/shutdown sequencing, or wherever there
is a requirement to control the output voltage On/Off status
with external circuitry.
The standby function is provided by the STBY* control
(pin 3). If pin 3 is left open-circuit the regulator operates
normally, and provides a regulated output at both Vo1 (pins
12–15) and Vo2 (pins 18–21) whenever a valid supply voltage is applied to Vin (pins 4, 5, & 6) with respect to GND
(pins 7-11). If a low voltage1 is then applied to pin-3 both
regulator outputs will be simultaneously disabled and the
input current drawn by the ISR will drop to a typical value
of 4mA. The standby control may also be used to hold-off
both regulator outputs during the period that input power is
applied.
The standby pin is ideally controlled using an open-collector
(or open-drain) discrete transistor (See Figure 1). The
open-circuit voltage is the input voltage +Vin. Table 1 gives
the circuit parameters for this control input.
Table 1 Standby Control Parameters
Parameter
Min
Enable (VIH)
Disable (VIL)
VSTBY (open circuit)
ISTBY (IIL)
—
–0.1V
—
—
1, 2
TYP
Max
—
—
+Vin 2
—
Open circuit
0.4V 1
—
–0.5mA
Figure 1
22
V 2 (sns)
V in
4, 5, 6
V o2
V IN
PT6984
V o1
18–21
Vo 2
12–15
Vo 1
STBY G N D
V 2 (adj) V 1 (adj)
7–11
23
3
16
+
C1
Q1
BSS138
+
C2
+
C3
Inhibit
COM
COM
Turn-On Time: Turning Q1 in Figure 1 off removes the lowvoltage signal at pin 3 and enables the PT6980 series
regulator. Following a delay of about 25ms, Vo1 and Vo2
rise together until the lower voltage, Vo2, reaches its set
output. Vo1 continues to rise until both outputs reach full
regulation voltage. The total power-up time is less than
40ms, and is relatively independent of load, temperature,
and output capacitance. Figure 2 shows waveforms of the
output voltages, Vo1 and Vo2, for a PT6984 (3.3V/1.2V).
The turn-off of Q1 corresponds to the rise in VSTBY. The
waveforms were measured with a 12V input voltage, and
with resistive loads of 5A and 1.25A at the Vo 1 and Vo 2
outputs respectively.
Figure 2
Notes:
1. The standby control input is Not compatible with TTL or
other devices that incorporate a totem-pole output drive. Use
only a true open-collector device, preferably a discrete bipolar
transistor (or MOSFET). To ensure the regulator output is
disabled, the control pin must be pulled to less than 0.4Vdc
with a low-level 0.5mA sink to ground.
V1 (1V/Div)
V2 (1V/Div)
Vstby (10V/Div)
2 The standby control input requires no external pull-up resistor.
The open-circuit voltage of the STBY* pin is the input
voltage +Vin.
3. When the regulator output is disabled the current drawn from
the input source is typically reduced to 4mA.
1
V 1 (sns)
HORIZ SCALE: 5ms/Div
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