TI PT4667A

PT4660 Series
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
Features
• Dual 15-A Outputs
(Independantly Regulated)
• Power-up/Down Sequencing
• Input Voltage Range:
36 V to 75 V
• 1500 VDC Isolation
• Temp Range: –40 to 100 °C
• High Efficiency: 88 %
• Fixed Frequency Operation
• Over-Current Protection
(Both Outputs)
• Dual Logic On/Off Control
• Over-Temperature Shutdown
• Over-Voltage Protection
(Coordinated Shutdown)
• Under-Voltage Lockout
• Input Differential EMI Filter
• IPC Lead Free 2
• Safety Approvals:
UL1950
CSA 22.2 950
Description
Ordering Information
The PT4660 Excalibur™ Series
is a 30-A rated, dual-output isolated
DC/DC converter that combines
state-of-the-art power conversion
technology with unparalleled flexibility. These modules operate from
a standard telecom (–48 V) central
office (CO) supply to produce two
independantly regulated outputs.
The PT4660 series is characterized
with high efficiencies and ultra-fast
transient response, and incorporates
many features to facilitate system
integration. These include a flexible
“On/Off” enable control, output
current limit, over-temperature
protection, and an input under-voltage
lockout (UVLO). In addition, both
output voltages are designed to meet
the power-up/power-down sequencing requirements of popular DSPs.
The PT4660 series is housed in
space-saving solderable copper case.
The package does not require a
heatsink and is available in both
vertical and horizontal configurations, including surface mount. The
‘N’ configuration occupies less than 2
in² of PCB area.
Pt. No.
PT4661o
PT4662o
PT4663o
PT4665o
PT4666o
PT4667o
PT4668o
Case/Pin
Configuration
Vertical
Horizontal
SMD
V 2 Adjust
20
Vo 2 adj
1
13
Vo 1 adj
Vo 1
+Vin
Vo 2
9–12
Vo 1
21–24
Vo 2
PT4660
3
4
2
L
O
A
D
EN 1*
EN 2
–Vin
* Inverted logic
For technical support and further information, visit http://power.ti.com
Order
Suffix
N
A
C
Package
Code
(EKD)
(EKA)
(EKC)
(Reference the applicable package code drawing for the dimensions and PC board layout)
V 1 Adjust
– V IN
Vo1/Vo2
5.0/3.3 Volts
3.3/2.5 Volts
3.3/1.8 Volts
3.3/1.5 Volts
2.5/1.8 Volts
5.0/1.8 Volts
3.3/1.2 Volts
PT Series Suffix (PT1234 x )
Typical Application
+ V IN
=
=
=
=
=
=
=
COM
14–19
COM
L
O
A
D
PT4660 Series
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
Pin-Out Information
Pin
Function
On/Off Logic
Pin
Function
Pin
Function
Pin 3
Pin 4
Output Status
1
+Vin
10
+Vo1
19
COM
1
×
Off
2
-Vin
11
+Vo1
20
Vo2 Adjust
0
1
On
3
EN 1
12
+Vo1
21
+Vo2
4
EN 2
13
Vo1 Adjust
22
+Vo2
×
0
Off
5
TEMP
14
COM
23
+Vo2
6
AUX
15
COM
24
+Vo2
7
Do Not Connect
16
COM
25
Do Not Connect
8
Do Not Connect
17
COM
26
Do Not Connect
9
+Vo1
18
COM
Notes:
Logic 1 =Open collector
Logic 0 = –Vin (pin 2) potential
For positive Enable function, connect pin 3
to pin 2 and use pin 4.
For negative Enable function, leave pin 4
open and use pin 3.
Note: Shaded functions indicate signals that are
referenced to the input (-Vin) potential.
Pin Descriptions
+Vin: The positive input supply for the module with respect
to –Vin. When powering the module from a –48 V telecom
central office supply, this input is connected to the primary
system ground.
–Vin: The negative input supply for the module, and the
0 VDC reference for the EN 1, EN 2, TEMP, and AUX
signals. When the module is powered from a +48-V supply,
this input is connected to the 48-V Return.
EN 1: This an open-collector (open-drain) negative logic
input that enables the module output. This pin is TTL
compatible and referenced to -Vin. A logic ‘0’ at this pin
enables the module’s outputs, and a logic ‘1’ or high
impedance disables the module’s outputs. If not used,
the pin must be connected to –Vin.
EN 2: An open-collector (open-drain) positive logic input
that enables the module output. This pin is TTL compatible and referenced to –Vin. A logic ‘1’ or high impedance
enables the module’s outputs. If not used, the pin should
be left open circuit.
AUX: Produces a regulated output voltage of 11.6 V ±5 %,
which is referenced to –Vin. The current drawn from the
pin must be limited to 10mA. The voltage may be used
to indicate the output status of the module to a primary
referenced circuit, or power a low-current amplifer.
TEMP: This is the output voltage produced by the module’s
internal temperature sensor. The voltage at this pin is
referenced to –Vin and rises approximately 10 mV/°C
from an intital value of 0.1 VDC at –40 °C.
Vtemp =0.5 + 0.01·Tsense
The signal is available whenever the module is supplied
with a valid input voltage, and is independant of the enable
logic status. (Note: A load impedance of less than 1 MΩ will
adversly affect the module’s over-temperature shutdown threshold.
Use a high-impedance input when monitoring this signal.)
Vo1: The higher regulated output voltage, which is referenced to the COM node.
Vo2: The lower regulated output voltage, which is referenced to the COM node.
COM: The secondary return reference for the module’s two
regulated output voltages. It is dc isolated from the input
supply pins.
Vo1 Adjust: Using a single resistor, this pin allows Vo1 to
be adjusted higher or lower than the preset value. If not
used, this pin should be left open circuit.
Vo2 Adjust: Using a single resistor, this pin allows Vo2 to
be adjusted higher or lower than the preset value. If not
used, this pin should be left open circuit.
For technical support and further information, visit http://power.ti.com
PT4660 Series
30-A Dual Output Isolated
DC/DC Converter
Specifications
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
(Unless otherwise stated, Ta =25 °C, Vin =48 V, & Io1=Io 2=10 A)
Characteristics
Symbols
Conditions
Output Current
Io1, Io2
Vo1
Io1+Io2
Vo2
Total (both outputs)
Input Voltage Range
Set Point Voltage Tolerance
Temperature Variation
Line Regulation
Load Regulation
Vin
Votol
∆Regtemp
∆Regline
∆Regload
Cross Regulation
∆Regcross
Total Output Variation
∆Votol
Efficiency
η
Vo Ripple (pk-pk)
Vr
Transient Response
ttr
Current Limit
Output Rise Time
Output Over-Voltage Protection
Output Voltage Adjustment
Switching Frequency
Under-Voltage-Lockout
ILIM
ton
OVP
∆Voadj
fs
UVLO
Internal Input Capacitance
Cin
Min
Vo1 ≤3.3 V
Vo1 =5.0 V
All voltages
Vo1 ≤3.3 V
Vo1 =5.0 V
–40 to +100 °C Case, Io1 =Io2 =0 A
Over Vin range with Io1=Io2=5 A
1 A ≤Io1 ≤Io1max, Io2 =1 A
1 A ≤Io2 ≤Io1max, Io1 =1 A
1 A ≤Io2 ≤Io1max, Io1 =1 A
1 A ≤Io1 ≤Io1max, Io2 =1 A
Includes set-point, line load,
–40 °C to +100 °C case
∆Vo1
∆Vo2
∆Vo1
∆Vo2
∆Vo1
∆Vo2
PT4661
PT4662
PT4663
PT4665
PT4666
PT4667
PT4668
Io1=Io2=5 A, 20 MHz bandwidth
Vo =5 V
Vo <5 V
1 A/µs load step from 50 % to 100 % Iomax
(either output)
Each output with other unloaded
At turn-on to within 90 % of Vo
Either output; shutdown and latch off
Vo1, Vo2
Rising
Falling
PT4660 SERIES
Typ
Max
0
0
0
0
0
36
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
15.5
—
—
—
270
—
30
—
—
—
—
—
48
±1
±0.5
±5
±2
±2
±2
±2
±2
±2
88
87
86
86
85
88
86
—
—
25
6.0
18
5
125 (1)
±10
—
34
32
15
10
15
30
25
75
±2
—
±10
±10
±10
±10
±5
±3
±3
—
—
—
—
—
—
—
75
50
100
—
—
10
—
—
330
36
—
—
2
—
3.5
0
—
—
—
0.8
Units
A
A
A
V
%Vo
%Vo
mV
mV
mV
%Vo
%
mVpp
µSec
%Vo
A
mSec
%Vo
%Vo
kHz
V
µF
Enable Control Inputs
Input High Voltage
Input Low Voltage
Input Low Current
Referenced to –Vin
VIH
VIL
IIL
—
0.5
—
mA
Standby Current
Iin standby
Pins 2, 3, & 4 connected
—
3
5
mA
External Output Capacitance
Primary/Secondary Isolation
Per each output
Operating Temperature Range
Over-Temperature Protection
Solder Reflow Temperature
Storage Temperature
Mechanical Shock
Mechanical Vibration
Ta
OTP
Treflow
Ts
—
—
Weight
Flammability
—
—
Over Vin range
Case temperature (auto restart)
Surface temperature of module pins or case
—
Per Mil-STD-883D, Method 2002.3
Per Mil-STD-883D, Method 2007.2, Suffix N
20–2,000 Hz
Suffixes A, C
—
Materials meet UL 94V-0
0
1500
—
10
—
—
–40
100
—
–40
—
—
—
—
—
—
1500
—
0.1 (3)
1.5 (3)
—
—
—
—
500
10 (6)
20 (6)
90
5,000
—
—
—
—
—
85 (4)
—
215 (5)
125
—
—
—
—
µF
V
pF
MΩ
Temperature Sense
Cout
V iso
C iso
R iso
Vtemp
Output voltage at temperatures:-
–40 °C
100 °C
(2)
V
V
°C
°C
°C
°C
G’s
G’s
grams
Notes: (1) This is a fixed parameter. Adjusting Vo1 or Vo2 higher will increase the module’s sensitivity to over-voltage detection. For more information, see the
application note on output voltage adjustment.
(2) The EN 1 and EN2 control inputs (pins 3 & 4) have internal pull-ups and may be controlled with an open-collector (or open-drain) transistor. Both
inputs are diode protected and can be connected to +Vin . The maximum open-circuit voltage is 5.4 V.
(3) Voltage output at “TEMP” pin is defined by the equation:- VTEMP = 0.5 + 0.01·T, where T is in °C. See pin descriptions for more information.
(4) See SOA curves or consult the factory for the appropriate derating.
(5) During solder reflow of SMD package version do not elevate the module case, pins, or internal component temperatures above a peak of 215 °C. For
further guidance refer to the application note, “Reflow Soldering Requirements for Plug-in Power Surface Mount Products,” (SLTA051).
(6) The case pins on the through-holed package types (suffixes N & A) must be soldered. For more information see the applicable package outline drawing.
For technical support and further information, visit http://power.ti.com
Typical Characteristics
PT4661—48 V
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
PT4661 (V1/V2 =5.0V/3.3V); Vin =48V
(See Notes A & B)
Efficiency vs I1out; I2out @1A, 3A, and 6A
Power Dissipation vs (Io1 + Io2)
100
20
90
16
80
6
3
1
70
Pd - Watts
Efficiency - %
I2 out
60
12
8
4
50
0
0
2
4
6
8
10
0
5
10
I1 out (A)
15
20
25
Io1 + Io2 (A)
Safe Operating Area: (Io1 + Io2)
Efficiency vs I1out; I2out @9A, 12A, and 15A
90
100
Efficiency - %
I2 out
80
9
12
15
70
60
Ambient Temperature (°C)
80
90
Airflow
70
300LFM
200LFM
100LFM
Nat Conv
60
50
40
30
20
50
0
2
4
6
8
0
10
5
10
15
20
25
Io1 + Io2 (A)
I1 out (A)
Cross Regulation: V1out vs I 2out @I1out =1A
5.05
V1 out (V)
5.025
5
4.975
4.95
0
3
6
9
12
15
I2 out (A)
Cross Regulation: V2out vs I 1out @I2out =1A
3.32
V2 out (V)
3.31
3.3
3.29
3.28
0
2
4
6
8
10
I1 out (A)
Note A: All Characteristic data in the above graphs has been developed from actual products tested at 25°C. This data is considered typical data for the converter.
Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and further information, visit http://power.ti.com
Typical Characteristics
PT4662—48 V
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
PT4662 (V1/V2 =3.3 V/2.5 V); Vin =48 V
(See Notes A & B)
Efficiency vs I1out; I2out @1 A, 3 A, and 6 A
Power Dissipation vs (Io 1 + Io2)
90
20
16
I2 out
6
3
1
80
Pd - Watts
Efficiency - %
85
12
8
75
4
70
0
0
3
6
9
12
15
0
6
12
I1 out (A)
18
24
30
Io1 + Io2 (A)
Safe Operating Area: (Io1 + Io 2)
Efficiency vs I1out; I 2out @9 A, 12 A, and 15 A
90
90
Efficiency - %
I2 out
9
12
15
80
75
Ambient Temperature (°C)
80
85
Airflow
70
300LFM
200LFM
100LFM
Nat conv
60
50
40
30
70
20
0
3
6
9
12
15
0
I1 out (A)
5
10
15
20
25
30
Io1 + Io2 (A)
Cross Regulation: V1out vs I2out @I1out =1 A
3.36
V1 out (V)
3.33
3.30
3.27
3.24
0
3
6
9
12
15
I2 out (A)
Cross Regulation: V2out vs I1out @I2out =1 A
2.530
V2 out (V)
2.515
2.500
2.485
2.470
0
3
6
9
12
15
I1 out (A)
Note A: All Characteristic data in the above graphs has been developed from actual products tested at 25 °C. This data is considered typical data for the converter.
Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and further information, visit http://power.ti.com
Typical Characteristics
PT4663—48 V
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
PT4663 (V1/V2 =3.3 V/1.8 V); Vin =48 V
(See Notes A & B)
Efficiency vs I1out; I2out @1 A, 3 A, and 6 A
Power Dissipation vs (Io1 + Io2)
20
90
16
I2 out
6
3
1
80
Pd - Watts
Efficiency - %
85
12
8
75
4
70
0
0
3
6
9
12
0
15
6
12
I1 out (A)
18
24
30
Io1 + Io2 (A)
Safe Operating Area: (Io1 + Io2)
Efficiency vs I 1out; I2out @9 A, 12 A, and 15 A
90
90
Efficiency - %
I2 out
9
12
15
80
75
Ambient Temperature (°C)
80
85
Airflow
70
300LFM
200LFM
100LFM
Nat Conv
60
50
40
30
20
70
0
3
6
9
12
0
15
5
10
15
20
25
30
Io1 + Io2 (A)
Iout (A)
Cross Regulation: V1out vs I2out @I1out =1 A
3.36
3.34
V1 out (V)
3.32
3.3
3.28
3.26
3.24
0
3
6
9
12
15
I2 out (A)
Cross Regulation: V2out vs I1out @I2out =1 A
1.82
V2 out (V)
1.81
1.8
1.79
1.78
0
3
6
9
12
15
I1 out (A)
Note A: All Characteristic data in the above graphs has been developed from actual products tested at 25 °C. This data is considered typical data for the converter.
Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and further information, visit http://power.ti.com
Typical Characteristics
PT4665—48 V
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
PT4665 (V1/V2 =3.3 V/1.5 V); Vin =48 V
(See Notes A & B)
Efficiency vs I 1out; I 2out @1 A, 3 A, and 6 A
Power Dissipation vs (Io1 + Io2)
100
20
16
I2 out
80
6
3
1
70
Pd - Watts
Efficiency - %
90
60
12
8
4
50
0
0
3
6
9
12
15
0
6
12
I1 out (A)
18
24
30
Io1 + Io2 (A)
Safe Operating Area: (Io1 + Io 2)
Efficiency vs I 1out; I 2out @9 A, 12 A, and 15 A
100
90
Efficiency - %
I2 out
80
9
12
15
70
60
Ambient Temperature (°C)
80
90
Airflow
70
300LFM
200LFM
100LFM
Nat Conv
60
50
40
30
50
20
0
3
6
9
12
15
0
I2 out (A)
5
10
15
20
25
30
Io1 + Io2 (A)
Cross Regulation: V1out vs I2out @I1out =1 A
3.32
V1 out (V)
3.31
3.3
3.29
3.28
0
3
6
9
12
15
I2 out (A)
Cross Regulation: V2out vs I1out @I2out =1 A
1.51
V2 out (V)
1.505
1.5
1.495
1.49
0
3
6
9
12
15
I1 out (A)
Note A: All Characteristic data in the above graphs has been developed from actual products tested at 25 °C. This data is considered typical data for the converter.
Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and further information, visit http://power.ti.com
Typical Characteristics
PT4666—48 V
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
PT4666 (V1/V2 =2.5 V/1.8 V); Vin =48 V
(See Notes A & B)
Efficiency vs I1out; I2out @1 A, 3 A, and 6 A
Power Dissipation vs I1out and I2out
100
10
90
8
80
6
3
1
70
Pd - Watts
Efficiency - %
I2 out
60
6
4
2
50
0
0
3
6
9
12
15
0
3
6
I1 out (A)
9
12
15
Io1 + Io2 (A)
Efficiency vs I1out; I2out @9 A, 12 A, and 15 A
Safe Operating Area: (Io1 + Io2)
100
90
Efficiency - %
I2 out
80
9
12
15
70
60
Ambient Temperature (°C)
80
90
Airflow
70
300LFM
200LFM
100LFM
Nat Conv
60
50
40
30
50
20
0
3
6
9
12
15
0
I1 out (A)
5
10
15
20
25
30
Io1 + Io2 (A)
Cross Regulation: V1out vs I2out @I1out =1 A
2.52
V1 out (V)
2.51
2.5
2.49
2.48
0
3
6
9
12
15
I2 out (A)
Cross Regulation: V2out vs I1out @I2out =1 A
1.81
V2 out (V)
1.805
1.8
1.795
1.79
0
3
6
9
12
15
I1 out (A)
Note A: All Characteristic data in the above graphs has been developed from actual products tested at 25 °C. This data is considered typical data for the converter.
Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and further information, visit http://power.ti.com
Typical Characteristics
PT4667—48 V
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
PT4667 (V1/V2 =5 V/1.8 V); Vin =48 V
(See Notes A & B)
Efficiency vs I 1out; I 2out @1 A, 3 A, and 6 A
Power Dissipation vs (Io1 + Io2)
100
20
16
I2 out
80
6
3
1
70
Pd - Watts
Efficiency - %
90
60
12
8
4
50
0
0
2
4
6
8
10
0
5
10
I1 out (A)
15
20
25
Io1 + Io2 (A)
Safe Operating Area: (Io1 + Io 2)
Efficiency vs I 1out; I 2out @9 A, 12 A, and 15 A
90
100
Efficiency - %
I2 out
80
9
12
15
70
60
Ambient Temperature (°C)
80
90
Airflow
70
300LFM
200LFM
100LFM
Nat conv
60
50
40
30
20
50
0
2
4
6
8
0
10
5
10
15
20
25
Io1 + Io2 (A)
I1 out (A)
Cross Regulation: V1out vs I2out @I1out =1 A
5.02
V1 out (V)
5.01
5
4.99
4.98
0
3
6
9
12
15
I2 out (A)
Cross Regulation: V2out vs I1out @I2out =1 A
1.81
V2 out (V)
1.805
1.8
1.795
1.79
0
2
4
6
8
10
I1 out (A)
Note A: All Characteristic data in the above graphs has been developed from actual products tested at 25 °C. This data is considered typical data for the converter.
Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and further information, visit http://power.ti.com
Typical Characteristics
PT4668—48 V
30-A Dual Output Isolated
DC/DC Converter
SLTS140C – MAY 2001 – REVISED OCTOBER 2003
PT4668 (V1/V2 =3.3 V/1.2 V); Vin =48 V
(See Notes A & B)
Efficiency vs I1out; I 2out @1 A, 3 A, and 6 A
Power Dissipation vs (Io 1 + Io2)
100
20
16
I2 out
80
6
3
1
70
Pd - Watts
Efficiency - %
90
60
12
8
4
50
0
0
3
6
9
12
0
15
6
12
18
24
30
Io1 + Io2 (A)
I1 out (A)
Efficiency vs I1out; I 2out @9 A, 12 A, and 15 A
Safe Operating Area: (Io1 + Io 2)
90
100
Efficiency - %
I2 out
80
9
12
15
70
60
Ambient Temperature (°C)
80
90
Airflow
70
300LFM
200LFM
100LFM
Nat Conv
60
50
40
30
20
50
0
3
6
9
12
0
15
5
10
15
20
25
30
Io1 + Io2 (A)
I1 out (A)
Cross Regulation: V1out vs I2out @I1out =1 A
3.32
V1 out (V)
3.31
3.3
3.29
3.28
0
3
6
9
12
15
I2 out (A)
Cross Regulation: V2out vs I1out @I2out =1 A
1.21
V2 out (V)
1.205
1.2
1.195
1.19
0
3
6
9
12
15
I1 out (A)
Note A: All Characteristic data in the above graphs has been developed from actual products tested at 25 °C. This data is considered typical data for the converter.
Note B: SOA curves represent operating conditions at which internal components are at or below manufacturer’s maximum rated operating temperatures.
For technical support and further information, visit http://power.ti.com
Application Notes
PT4660 & PT4680 Series
Operating Features & System Considerations for the
PT4660 & PT4680 Dual-Output Converters
Over-Current Protection
The dual-outputs of the PT4660 and PT4680 series of
DC/DC converters have independent output voltage
regulation and current limit control. Applying a load
current in excess of the current limit threshold at either
output will cause the respective output voltage to drop.
However, the voltage at Vo2 is derived from Vo1. Therefore a current limit fault on Vo1 will also cause Vo2 to
drop. Conversely, a current limit fault applied to Vo 2
will only cause Vo2 voltage to drop, and Vo1 will remain
in regulation.
The current limit is continuous with some current foldback. This means that at short circuit, the value of the
output current can be less than the rated output of the
converter. This is to reduce power dissipation when a fault
is present. As with any foldback-limited source, if a constant current load is applied to the converter with a value
greater than the short-circuit current, the output voltage
will not come up. Resistive and non-linear load circuits
are not affected by this characteristic as long as the current at startup does not exceed the short-circuit current
of the converter. The majority of low-voltage analog
and digital applications are not affected by this restriction. However, when testing with an electronic load the
constant resistance setting should be used.
Output Over-Voltage Protection
Each output is monitored for over voltage (OV). For fail
safe operation and redundancy, the OV fault detection
circuitry uses a separate reference to the voltage regulation circuits. The OV threshold is fixed, and set nominally
25 % higher than the set-point output voltage. If either
output exceeds the threshold, the converter is shutdown
and must be actively reset. The OV protection circuit
can be reset by momentarily turning the converter off.
This is accomplished by either cycling one of the output
enable control pins (EN1 or EN2), or by removing the
input power to the converter. Note: If Vo1 or Vo2 is adjusted
to a higher voltage, the margin between the respective steadystate output voltage and its OV threshold is reduced. This can
make the module sensitive to OV fault detection, that may
result from random noise and load transients.
Over-Temperature Protection
The converter has an internal temperature sensor. At a
case temperature of approximately 115 °C the converter
will shut down, and will automatically restart when the
temperature returns to about 100 °C. The analog voltage
generated by the sensor is also made available at the
TEMP output (pin 5), and can be monitored by the
For technical support and further information, visit http://power.ti.com
host system for diagnostic purposes. Consult the ‘Pin
Descriptions’ section of the data sheet for further information on this feature.
Under-Voltage Lock-Out
The Under-Voltage Lock-Out (UVLO) circuit prevents
operation of the converter whenever the input voltage to
the module is insufficient to maintain output regulation.
The UVLO has approximately 2 V of hysterisis. This is
to prevent oscillation with a slowly changing input voltage. Below the UVLO threshold the module is off and
the enable control inputs, EN1 and EN2 are inoperative.
Primary-Secondary Isolation
The PT4460 and PT4680 series of DC/DC converters
incorporate electrical isolation between the input terminals (primary) and the output terminals (secondary). All
converters are production tested to a withstand voltage
of 1500 VDC. The isolation complies with UL60950 and
EN60950, and the requirements for operational isolation.
This allows the converter to be configured for either a
positive or negative input voltage source.
The regulation control circuitry for these modules is
located on the secondary (output) side of the isolation
barrier. Control signals are passed between the primary
and secondary sides of the converter via a proprietory
magnetic coupling scheme. This eliminates the use of
opto-couplers. The data sheet ‘Pin Descriptions’ and
‘Pin-Out Information’ provides guidance as to which
reference (primary or secondary) that must be used for
each of the external control signals.
Fuse Requirements
To comply with safety agency requirements, these converters must be operated with an external input fuse.
A fast-acting 250-V fuse is required. Table 1-1 gives
the recommended current rating for the product series
being used.
Table 1-1; Recommended Fuse Rating
Product
Input
Total
Series
Bus
Iout
Fuse
Rating
PT4660
PT4680
7A
10 A
48 V
24 V
30 A
20 A
Application Notes
PT4660 & PT4680 Series
Using the On/Off Enable Controls on the PT4660
& PT4680 Series of Dual-Output Converters
The PT4660 (48V input) and PT4680 (24V input) series of dual-output DC/DC converters incorporate
both positive and negative logic output enable controls.
EN1 (pin 3) is the negative enable input, and EN2 (pin 4)
is the positive enable input. Both inputs are TTL logic
compatible, and are electrically referenced to -Vin (pin 2)
on the primary (input) side of the converter. A pull-up
resistor is not required, but may be added if desired.
Adding a pull-up resistor from either EN1 or EN2, up to
+Vin, will not damage the converter.
the outputs of the converter. An example of this configuration is detailed in Figure 2-2. Note: The converter will
only produce and output voltage if a valid input voltage is
applied to ±Vin.
Figure 2-2; Negative Enable Configuration
3
4
EN 1*
EN 2
PT4660
1 =Outputs On
BSS138
– V IN
Automatic (UVLO) Power-Up
Connecting EN1 (pin 3) to -Vin (pin 2) and leaving EN2
(pin 4) open-circuit configures the converter for automatic
power up. (See data sheet “Typical Application”). The
converter control circuitry incorporates an “Under Voltage
Lockout” (UVLO) function, which disables the output
until the minimum specified input voltage is present
(See data sheet Specifications). The UVLO circuitry
ensures a clean transition during power-up and powerdown, allowing the converter to tolerate a slow-rising
input voltage. For most applications EN1 and EN2, can
be configured for automatic power-up.
Positive Output Enable (Negative Inhibit)
To configure the converter for a positive enable function,
connect EN1 (pin 3) to -Vin (pin 2), and apply the system
On/Off control signal to EN2 (pin 4). In this configuration, a logic ‘0’ (-Vin potential) applied to pin 4 disables
the converter outputs. An example of this configuration
is detailed in Figure 2-1.
Figure 2-1; Positive Enable Configuration
3
2
–Vin
On/Off Output Voltage Sequencing
The output voltages from these dual-output DC/DC
converters are independantly regulated, and are internally sequenced to meet the power-up requirements of
popular microprocessor and DSP chipsets. Figure 2-3
shows the waveforms from a PT4661 after the converter
is enabled at t=0s. During power-up, the Vo1 and Vo 2
voltage waveforms typically track within 0.4V prior to
Vo2 reaching regulation. The waveforms were measured
with a 5-Adc resistive load at each output, and with a
48-VDC input source applied. The converter typically
produces a fully regulated output within 25ms. The
actual turn-on time will vary slightly with input voltage,
but the power-up sequence is independent of the load at
either output.
Figure 2-3; Vo1, Vo2 Power-Up Sequence
Vo1 (2V/Div)
EN 1*
Vo2 (2V/Div)
4
EN 2
PT4660
IIN (0.5A/Div)
1 =Outputs Off
BSS138
– V IN
2
–Vin
0
5
10
15
20
25
30
35
t (milliseconds)
Negative Output Enable (Positive Inhibit)
To configure the converter for a negative enable function,
EN2 (pin 4) is left open circuit, and the system On/Off
control signal is applied to EN1 (pin 3). A logic ‘0’ (-Vin
potential) must then be applied to pin 3 in order to enable
During turn-off, both outputs drop rapidly due to the
discharging effect of actively switched rectifiers. The
voltage at Vo 1 remains higher than Vo2 during this
period. The discharge time is typically 100µs, but will
vary with the amount of external load capacitance.
For technical support and further information, visit http://power.ti.com
Application Notes
PT4660 & PT4680 Series
Adjusting the Output Voltage of the PT4660
& PT4680 Series of Dual-Output Converters
3. Vo2 must always be at least 0.3 V lower than Vo1.
4. The over-voltage protection threshold is fixed, and is set
nominally 25 % above the set-point output voltage.
Adjusting Vo1 or Vo2 higher will reduce the voltage
margin between the respective steady-state output
voltage and its over-voltage (OV) protection threshold.
This could make the module sensitive to OV fault
detection, as a result of random noise and load transients.
Note: An OV fault is a latched condition that shuts down
both outputs of the converter. The fault can only be cleared
by cycling one of the Enable control pins (EN1* / EN2), or
by momentarily removing the input power to the module.
The dual output voltages from the PT4660 (48-V Bus),
and PT4680 (24-V Bus) series of DC/DC converters can
be independently adjusted by up to 10 %, higher or lower
than the factory trimmed pre-set voltage. The adjustment
method requires the addition of a single external resistor 1.
Table 3-1 gives the adjustment range of Vo1 and Vo2 for
each model in the series as Va(min) and Va(max).
Vo1 Adjust Down: Add a resistor (R1), between pin 13
(Vo1 Adj) and pin 12 (Vo1) 2.
Vo1 Adjust Up: To increase the output, add a resistor R2
between pin 13 (Vo1 Adj) and pin 14 (COM) 2, 4.
5. Never connect capacitors to either the Vo1 Adj or
Vo2 Adj pins. Any capacitance added to these control
pins will affect the stability of the respective regulated
output.
Vo2 Adjust Down: Add a resistor (R3) between pin 20
(Vo2 Adj) and pin 21 (Vo2) 2.
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 3-1 for the
output and model being adjusted.
Vo2 Adjust Up: Add a resistor R4 between pin 20
(Vo2 Adj) and pin 19 (COM) 2, 4.
Refer to Figure 3-1 and Table 3-2 for both the placement and
value of the required resistor.
Notes:
1. Adjust resistors are not required if Vo1 and Vo2 are to
remain at their respective nominal set-point voltage.
In this case, Vo1 Adj (pin 13) and Vo2 Adj (pin 20) are
left open-circuit
2. Use only a single 1% resistor in either the (R1) or R2
location to adjust Vo1, and in the (R3) or R4 location
to adjust Vo2. Place the resistor as close to the converter
as possible.
(R1) or (R3)
=
Ro · (Va – Vr )
(Vo – Va)
R2 or R4
=
Ro ·
Where: Vo
Va
Vr
Ro
Rs
=
=
=
=
=
Vr
Va – Vo
Vo 1
1
+Vin
Vo 2
9–12
V o1
21–24
V o2
(R1)
PT4660
V o 1 adj
3
4
– V IN
2
EN 1*
EN 2
V o 2 adj
* Inverted logic
For technical support and further information, visit http://power.ti.com
L
O
A
D
20
R2
COM
(R3)
13
–Vin
14–19
kΩ
– Rs
kΩ
Original output voltage, (Vo1 or Vo2)
Adjusted output voltage
The reference voltage from Table 3-1
The resistance constant in Table 3-1
The series resistance from Table 3-1
Figure 3-1; Placement of Output Adjust Resistors
+ V IN
– Rs
R4
COM
L
O
A
D
Application Notes
PT4660 & PT4680 Series
Table 3-1; ADJUSTMENT RANGE AND FORMULA PARAMETERS
Vo1 Bus
24 V Bus Pt.#
48 V Bus Pt.#
Adj. Resistor
Vo(nom)
Va(min)
Va(max)
Vr
Ω)
Ro (kΩ
Ω)
Rs (kΩ
PT4681/7
PT4661/7
(R1)/R2
PT4682/3/5/8
PT4662/3/5/8
(R1)/R2
PT4686
PT4666
(R1)/R2
Vo2 Bus (2)
PT4681
PT4661
(R3)/R4
PT4682
PT4662
(R3)/R4
PT4683/7
PT4663/7
(R3)/R4
PT4686
PT4666
(R3)/R4
PT4685
PT4665
(R3)/R4
PT4668
(R3)/R4
5.0 V
4.5 V
5.5 V
2.5 V
4.99
20.0
3.3 V
2.97 V
3.63 V
1.65 V
4.99
20.0
2.5 V
2.25 V
2.75 V
1.25
4.99
20.0
3.3 V
2.97 V
3.63 V
1.65 V
1.21
4.99
2.5 V
2.25 V
2.75 V
1.25 V
1.21
4.99
1.8 V
1.62 V
1.98 V
0.9 V
1.21
4.99
1.8 V
1.62 V
1.98 V
0.9 V
1.21
3.32
1.5 V
1.35 V
1.65 V
0.75 V
1.21
4.99
1.2 V
1.08 V
1.32 V
0.6V
1.21
3.32
Table 3-2a; ADJUSTMENT RESISTOR VALUES, Vo1
24 V Bus Pt.# PT4681/7
48 V Bus Pt.# PT4661/7
Adj. Resistor
(R1)/R2
Vo(nom)
Va(req’d)
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
4.7
4.6
4.5
PT4682/3/5
PT4662/3/5/8
(R1)/R2
5.0 V
5.0 kΩ
11.2 kΩ
21.6 kΩ
42.4 kΩ
105.0 kΩ
(99.8) kΩ
(37.4) kΩ
(16.6) kΩ
(6.2) kΩ
(0.0)
PT4686
PT4666
(R1)/R2
3.3 V
Va(req’d)
3.6
3.54
3.48
3.42
3.36
3.3
3.24
3.18
3.12
3.06
3.0
7.4 kΩ
14.3 kΩ
25.7 kΩ
48.6 kΩ
117.0 kΩ
(112.0 kΩ)
(43.6 kΩ)
(20.8 kΩ)
(9.3 kΩ)
(2.5 kΩ)
2.5 V
Va(req’d)
2.75
2.7
2.65
2.6
2.55
2.5
2.45
2.4
2.35
2.3
2.25
5.0 kΩ
11.2 kΩ
21.6 kΩ
42.4 kΩ
105.0 kΩ
(99.8 kΩ)
(37.4 kΩ)
(16.6 kΩ)
(6.2 kΩ)
(0.0 kΩ)
R1 = (Blue), R2 = Black
Table 3-2b; ADJUSTMENT RESISTOR VALUES, Vo2
24 V Bus Pt.# PT4681
48 V Bus Pt.# PT4661
Adj. Resistor
(R3)/R4
Vo(nom)
Va(req’d)
3.6
3.54
3.48
3.42
3.36
3.3
3.24
3.18
3.12
3.06
3.0
2.75
2.7
2.65
2.6
2.55
2.5
2.45
2.4
2.35
2.3
2.25
3.3 V
PT4682
PT4662
(R3)/R4
2.5 V
1.7 kΩ
3.3 kΩ
6.1 kΩ
11.6 kΩ
28.3 kΩ
(27.1) kΩ
(10.4) kΩ
(4.9) kΩ
(2.1) kΩ
(0.5) kΩ
1.1 kΩ
2.6 kΩ
5.1 kΩ
10.1 kΩ
25.3 kΩ
(24.1) kΩ
(8.9) kΩ
(3.9) kΩ
(1.4) kΩ
(0.0)kΩ
Va(req’d)
1.95
1.9
1.85
1.8
1.75
1.7
1.65
1.6
1.55
1.5
1.45
1.4
1.35
1.3
1.275
1.25
1.225
1.2
1.175
1.15
1.125
1.1
PT4683/6/7
PT4663/6/7
(R3)/R4
PT4686
PT4666
(R3)/R4
PT4685
PT4665
(R3)/R4
PT4668
(R3)/R4
1.8 V
1.8 V
1.5 V
1.2 V
2.3 kΩ
5.9 kΩ
16.8 kΩ
3.9 kΩ
7.6 kΩ
18.5 kΩ
(15.6) kΩ
(4.7) kΩ
(1.1) kΩ
(17.3) kΩ
(6.4) kΩ
(2.7) kΩ
1.1 kΩ
4.1 kΩ
13.2 kΩ
(12.0) kΩ
(2.9) kΩ
(0.0) kΩ
3.9 kΩ
6.4 kΩ
11.2 kΩ
25.7 kΩ
(24.5) kΩ
(10.0) kΩ
(5.2) kΩ
(2.7) kΩ
R3 = (Blue), R4 = Black
For technical support and further information, visit http://power.ti.com
PACKAGE OPTION ADDENDUM
www.ti.com
24-Jun-2005
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
PT4661A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4661C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4661N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4662A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4662C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4662N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4663A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4663C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4663N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4665A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4665C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4665N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4666A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4666C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4666N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4667A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4667C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4667N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4668A
ACTIVE
SIP MOD
ULE
EKA
26
6
TBD
Call TI
Level-1-215C-UNLIM
PT4668C
ACTIVE
SIP MOD
ULE
EKC
26
6
TBD
Call TI
Level-3-215C-168HRS
PT4668N
ACTIVE
SIP MOD
ULE
EKD
26
6
TBD
Call TI
Level-1-215C-UNLIM
(1)
Lead/Ball Finish
MSL Peak Temp (3)
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.
Addendum-Page 1
PACKAGE OPTION ADDENDUM
www.ti.com
24-Jun-2005
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) 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.
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.
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Addendum-Page 2
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