TI PTH12020LAZ

PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
18-A, 12-V INPUT NON-ISOLATED WIDE-OUTPUT
ADJUST POWER MODULE
FEATURES
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Up to 18 A Output Current
12-V Input Voltage
Wide-Output Voltage Adjust (1.2 V to
5.5 V)/(0.8 V to 1.8 V)
Efficiencies up to 95%
195 W/in3 Power Density
On/Off Inhibit
Output Voltage Sense
Pre-Bias Startup
Under-Voltage Lockout
Auto-Track™ Sequencing
Margin Up/Down Controls
Output Over-Current Protection
(Non-Latching, Auto-Reset)
Over-Temperature Protection
Operating Temperature: –40°C to 85°C
Safety Agency Approvals: UL/cUL 60950,
EN60950 VDE
•
Point-of-Load Alliance (POLA™) Compatible
APPLICATIONS
•
Complex multi-voltage, multi-processor
systems
NOMINAL SIZE =
1.5 in x 0.87 in
(38,1 mm x 22,1 mm)
DESCRIPTION
The PTH12020 series of non-isolated power modules offers OEM designers a combination of high performance,
small footprint, and industry leading features. As part of a new class of power modules, these products provide
designers with the flexibility to power the most complex multi-processor digital systems using off-the-shelf catalog
parts.
The series employs double-sided surface mount construction and provides highperformance step-down power
conversion for up to 18 A of output current from a 12-V input bus voltage. The output voltage of the W-suffix
parts can be set to any value over the range, 1.2 V to 5.5 V. The L-suffix parts have an adjustment range of
0.8 V to 1.8 V. The output voltage is set using a single resistor.
This series includes Auto-Track™ sequencing. Auto-Track sequencing simplifies the task of supply voltage
sequencing in a power system by enabling modules to track each other, or any external voltage, during power up
and power down.
Other operating features include an on/off inhibit, output voltage adjust (trim), margin up/down controls, and the
ability to start up into an existing output voltage or prebias. For improved load regulation, an output voltage sense
is provided. A non-latching over-current trip and overtemperature shutdown feature protects against load faults.
Target applications include complex multivoltage, multiprocessor systems that incorporate the industry's
high-speed DSPs, microprocessors and bus drivers.
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.
POLA, TMS320 are trademarks of Texas Instruments.
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2003–2005, Texas Instruments Incorporated
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
These devices have limited built-in ESD protection. The leads should be shorted together or the device
placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
STANDARD APPLICATION
Track
Margin Down
Margin Up
10 9 8
1
2
VIN
7
PTH12020x
(T o p V i ew)
3 4 5
VO Sense
Inhibit
+
CIN
560 mF
(Required)
VOUT
6
RSET
+ C
OUT
330 mF
(Optional)
GND
L
O
A
D
GND
ORDERING INFORMATION
PTH12020 (Base Part Number)
Output Voltage Range
1.2 V–5.5 V (Adjustable)
0.8 V–1.8 V (Adjustable)
(1)
(2)
(3)
(4)
2
Part Number
(1)
DESCRIPTION
Pb – Free and RoHS
Mechanical Package
(2)
PTH12020WAH
Horizontal T/H
Yes
(3)
PTH12020WAS
Standard SMD
No
(4)
EUL
PTH12020WAZ
Optional SMD
Yes
(3)
EUL
EUK
EUK
PTH12020LAH
Horizontal T/H
Yes
(3)
PTH12020LAS
Standard SMD
No
(4)
EUL
PTH12020LAZ
Optional SMD
Yes
(3)
EUL
Add T to end of part number for tape and reel on SMD packages only.
Reference the applicable package reference drawing for the dimensions and PC board layout.
Lead (Pb) – free option specifies Sn/Ag pin solder material.
Standard option specifies 63/37, Sn/Pb pin solder material.
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
ABSOLUTE MAXIMUM RATINGS
over operating free-air temperature range unless otherwise noted
(1)
UNIT
Vtrack
Track input
–0.3V to VI +0.3 V
Vinh
Inhibit control input
TA
Operating temperature
range
Over VI Range
Twave
Wave solder temperature
Surface temperature of module body or pins
(5 seconds)
Treflow
Solder reflow temperature
Surface temperature of module body or pins
Tso
Storage temperature
–0.3 V to 7 V
–40°C to 85°C
PTH12020WAH
260°C
(2)
PTH12020WAS
235°C
(2)
PTH12020WAZ
260°C
(2)
–40°C to 125°C
Mechanical shock
Per Mil-STD-883D, Method 2002.3 1 msec, 1/2 Sine, mounted
Mechanical vibration
Mil-STD-883D, Method 2007.2 20-2000 Hz
500 G
20 G
Weight
7 grams
Flammability
(1)
(2)
Meets UL 94V-O
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.
During soldering of package version, do not elevate peak temperature of the module, pins or internal components above the stated
maximum.
ELECTRICAL CHARACTERISTICS
TA = 25°C, VI =12 V, VO = 3.3 V, CI = 560 µF, CO = 0 µF, and Io = Iomax) (unless otherwise noted)
PARAMETER
IO
Output current
PTH12020W
TEST CONDITIONS
MIN
TYP
MAX
60°C, 200 LFM airflow
0
18 (1)
25°C, natural convection
0
18 (1)
Input voltage range
Votol
Set-point voltage tolerance
∆Regtemp
Temperature variation
–40°C <TA < 85°C
∆Regline
Line regulation
Over Vin range
±5
mV
∆Regload
Load regulation
Over Io range
±5
mV
∆Regtot
Total output variation
Includes set-point, line, load, –40°C ≤ TA≤ 85°C
∆Vadj
Output voltage adjust range
Over Vin range
Efficiency
IO = 12 A
Vr
Transient response
20 MHz bandwidth
Io trip
Over-current threshold
Reset, followed by auto-recovery
Transient response
1 A/µs load step, 50 to
100% Iomax,Cout =330 µF
ttr
∆Vtr
∆Vomargin
Margin up/down adjust
IIL margin
Margin input current (pins 9 /10)
Pin to GND
IIL track
Track input current (pin 8)
Pin to GND
dVtrack/dt
Track slew rate capability
Cout≤ Cout(max)
(1)
(2)
(3)
10.8
A
Vin
η
Over Io range
UNIT
13.2
V
±2 (2)
%Vo
%Vo
±0.5
±3 (2)
1.2
5.5
RSET = 280 Ω, Vo = 5.0 V
95%
RSET = 2.0 kΩ, Vo = 3.3 V
93%
RSET = 4.32 kΩ, Vo = 2.5 V
92%
RSET = 11.5 kΩ, Vo = 1.8 V
90%
%Vo
V
RSET = 24.3 kΩ, Vo = 1.5 V
88%
RSET = open ckt., Vo = 1.2 V
86%
Vo ≤ 2.5 V
32
mVpp
Vo > 2.5 V
1
%Vo
30
A
Recovery time
70
µSec
Vo over/undershoot
70
mV
±5%
–8
(3)
µA
–0.13
(3)
mA
1
V/ms
See SOA curves or consult factory for appropriate derating.
The set-point voltage tolerance is affected by the tolerance and stability of RSET. The stated limit is unconditionally met if RSET has a
tolerance of 1%, with 100 ppm/°C or better temperature stability.
A small low-leakage (<100 nA) MOSFET is recommended to control this pin. The open-circuit voltage is less than 1 Vdc.
3
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
ELECTRICAL CHARACTERISTICS (continued)
TA = 25°C, VI =12 V, VO = 3.3 V, CI = 560 µF, CO = 0 µF, and Io = Iomax) (unless otherwise noted)
PARAMETER
UVLO
Undervoltage lockout
VIH
Inhibit control (pin 3)
Input high voltage
VIL
Input low voltage
Pin to GND
Input standby current
Inhibit (pin 3) to GND, Track (pin 8) open
ƒs
Switching frequency
Over Vin and Io ranges
CI
External input capacitance
Reliability
(5)
(6)
(7)
(8)
9.7
10.4
8.8
9.2
2
Open (4)
–0.2
0.5
260
560
Capacitance value
0
Ceramic
0
4
Per Bellcore TR-332, 50% stress, TA = 40°C, ground benign
UNIT
V
V
0.24
mA
5
mA
320
380
(5)
Non-ceramic
Equivalent series resistance (non-ceramic)
(4)
MAX
Referenced to GND
Input low current
MTBF
TYP
Vin decreasing
IIL inhibit
External output capacitance
MIN
Vin increasing
Iin inh
CO
PTH12020W
TEST CONDITIONS
kHz
µF
330
(6)
9900
(7)
300
µF
mΩ
(8)
5.3
106 Hrs
This control pin is pulled up to an internal supply voltage. To avoid risk of damage to the module, do not apply an external voltage
greater than 7 V. If this input is left open-circuit the module will operate when input power is applied. A small low-leakage (<100 nA)
MOSFET or open-drain/collector voltage supervisor IC is recommended for control. For further information, consult the related
application note.
A 560 µF electrolytic input capacitor is required for proper operation. The capitor must be rated for a minimum of 800 mA rms of ripple
current.
An external output capacitor is not required for basic operation. Adding 330 µF of distributed capacitance at the load will improve the
transient response.
This is the calculated maximum. The minimum ESR limitation will often result in a lower value. When controlling the Track pin using a
voltage supervisor, the maximum output capacitance is reduced to 6600 µF. Consult the application notes for further guidance.
This is the typical ESR for all the electrolytic (non-ceramic) output capacitance. Use 7 mΩ as the minimum when using max-ESR values
to calculate.
ELECTRICAL CHARACTERISTICS
TA = 25°C, VI =12 V, VO = 3.3 V, CI = 560 µF, CO = 0 µF, and Io = Iomax) (unless otherwise noted)
PARAMETER
IO
Output current
PTH12020L
TEST CONDITIONS
MIN
TYP
MAX
60°C, 200 LFM airflow
0
18 (1)
25°C, natural convection
0
18 (1)
Input voltage range
Votol
Set-point voltage tolerance
∆Regtemp
Temperature variation
–40°C <TA < 85°C
±0.5
%Vo
∆Regline
Line regulation
Over Vin range
±5
mV
∆Regload
Load regulation
Over Io range
±5
∆Regtot
Total output variation
Includes set-point, line, load, –40°C ≤ TA≤ 85°C
∆Vadj
Output voltage adjust range
Over Vin range
Efficiency
IO = 12 A
Vo ripple (pk-pk)
20 MHz bandwidth
Io trip
Over-current threshold
Reset, followed by auto-recovery
Transient response
1 A/µs load step, 50 to
100% Iomax,Cout = 330 µF
∆Vtr
∆Vomargin
(1)
(2)
4
Margin up/down adjust
13.2
±2
Vr
ttr
10.8
A
Vin
η
Over Io range
UNIT
89%
RSET = 3.57 kΩ, Vo = 1.5 V
87%
RSET = 12.1 kΩ, Vo = 1.2 V
85%
RSET = 32.4 kΩ, Vo = 1.0 V
83%
RSET = open cct., Vo = 0.8 V
80%
Vo > 2.5 V
Recovery time
Vo over/undershoot
(2)
1.8
RSET = 130 Ω, Vo = 1.8 V
1
V
%Vo
mV
±3
0.8
(2)
%Vo
V
%Vo
30
A
70
µSec
70
mV
±5%
See SOA curves or consult factory for appropriate derating.
The set-point voltage tolerance is affected by the tolerance and stability of RSET. The stated limit is unconditionally met if RSET has a
tolerance of 1%, with 100 ppm/°C or better temperature stability.
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
ELECTRICAL CHARACTERISTICS (continued)
TA = 25°C, VI =12 V, VO = 3.3 V, CI = 560 µF, CO = 0 µF, and Io = Iomax) (unless otherwise noted)
PARAMETER
IIL margin
Margin input current (pins 9 /10)
Pin to GND
IIL track
Track input current (pin 8)
Pin to GND
dVtrack/dt
Track slew rate capability
Cout≤ Cout(max)
Undervoltage lockout
VIH
Inhibit control (pin 3)
Input high voltage
VIL
Input low voltage
IIL inhibit
Input low current
Pin to GND
Iin inh
Input standby current
Inhibit (pin 3) to GND, Track (pin 8) open
ƒs
Switching frequency
Over Vin and Io ranges
CI
External input capacitance
External output capacitance
MTBF
Reliability
(3)
(4)
(5)
(6)
(7)
(8)
MIN
TYP
MAX
–8 (3)
1
9.7
Vin decreasing
8.8
Referenced to GND
10.4
9.2
2
Open (4)
–0.2
0.5
200
Capacitance value
0
Ceramic
0
mA
V/ms
V
V
0.24
mA
5
mA
250
300
560 (5)
Non-ceramic
UNIT
µA
–0.13 (3)
Vin increasing
UVLO
CO
PTH12020L
TEST CONDITIONS
kHz
µF
330
(6)
9900
(7)
300
µF
Equivalent series resistance (non-ceramic)
4 (8)
mΩ
Per Bellcore TR-332, 50% stress, TA = 40°C, ground benign
5.3
106 Hrs
A small low-leakage (<100 nA) MOSFET is recommended to control this pin. The open-circuit voltage is less than 1 Vdc.
This control pin is pulled up to an internal supply voltage. To avoid risk of damage to the module, do not apply an external voltage
greater than 7 V. If this input is left open-circuit the module will operate when input power is applied. A small low-leakage (<100 nA)
MOSFET or open-drain/collector voltage supervisor IC is recommended for control. For further information, consult the related
application note.
A 560 µF electrolytic input capacitor is required for proper operation. The capitor must be rated for a minimum of 800 mA rms of ripple
current.
An external output capacitor is not required for basic operation. Adding 330 µF of distributed capacitance at the load will improve the
transient response.
This is the calculated maximum. The minimum ESR limitation will often result in a lower value. When controlling the Track pin using a
voltage supervisor, the maximum output capacitance is reduced to 6600 µF. Consult the application notes for further guidance.
This is the typical ESR for all the electrolytic (non-ceramic) output capacitance. Use 7 mΩ as the minimum when using max-ESR values
to calculate.
5
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
PTH12020W TYPICAL CHARACTERISTICS (VIN = 12 V) (1) (2)
EFFICIENCY
vs
LOAD CURRENT
OUTPUT RIPPLE
vs
LOAD CURRENT
100
100
6
VO = 1.2 V
VO = 1.5 V
VO = 1.8 V
VO = 2 V
VO = 2.5 V
VO = 3.3 V
VO = 5 V
(See Note A)
Output Ripple − mV
VO = 5 V
VO = 3.3 V
VO = 2.5 V
VO = 2 V
VO = 1.8 V
VO = 1.5 V
VO = 1.2 V
80
70
60
80
(See Note A)
PD− Power Dissipation − W
90
90
Efficiency − %
POWER DISSIPATION
vs
LOAD CURRENT
70
60
VO = 5 V
VO = 3.3 V
5
VO = 2.5 V
VO = 2 V
4
3
VO = 1.8 V
2
VO = 1.5 V
VO = 1.2 V
1
(See Note A)
0
3
6
9
12
15
50
18
0
3
0
18
0
10
15
TEMPERATURE DERATING
vs
OUTPUT CURRENT
TEMPERATURE DERATING
vs
OUTPUT CURRENT
TEMPERATURE DERATING
vs
OUTPUT CURRENT
400 LFM
70
200 LFM
100 LFM
60
Nat Conv
50
40
VO = 5 V
(See Note B)
30
20
3
6
9
12
IO − Load Current − A
Figure 4.
15
18
80
80
400 LFM
70
200 LFM
100 LFM
60
Nat Conv
50
40
30
20
0
15
90
90
0
5
IO − Load Current − A
Figure 3.
TA− Ambient Temperature − 5 C
TA− Ambient Temperature 5−C
15
Figure 2.
80
6
12
Figure 1.
90
(2)
9
IO − Load Current − A
IO − Load Current − A
(1)
6
TA− Ambient Temperature − 5 C
50
VO = 2.5 V
(See Note B)
3
6
9
12
IO − Load Current − A
Figure 5.
15
18
400 LFM
70
200 LFM
100 LFM
60
Nat Conv
50
40
30
20
VO = 1.8 V
(See Note B)
0
3
6
9
12
15
18
IO − Load Current − A
Figure 6.
The electrical characteristic data has been developed from actual products tested at 25°C. This data is considered typical for the
converter. Applies to Figure 1, Figure 2, and Figure 3.
The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum
operating temperatures. Derating limits apply to modules soldered directly to a 4 inch × 4 inch double-sided PCB with 1oz. copper. For
surface mount products (AS and AZ suffix), multiple vias (plated through holes) are required to add thermal paths around the power
pins. Please refer to the mechanical specification for more information. Applies to Figure 4, Figure 5 and Figure 6.
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
PTH12020L TYPICAL CHARACTERISTICS (VIN = 12 V) (3) (4)
EFFICIENCY
vs
LOAD CURRENT
OUTPUT RIPPLE
vs
LOAD CURRENT
70
Output Ripple − mV
Output Ripple − mV
VO = 1 V
VO = 1.2 V
VO = 1.5 V
VO = 1.8 V
30
VO = 1V
20
VO = 0.8 V
(See Note A)
0
0
3
6
9
12
15
18
VO = 1.5 V
3
2
VO = 0.8 V
1
10
60
VO = 1.8 V
4
40
80
VO = 0.8 V
(See Note A)
(See Note A)
VO = 1.5 V
VO = 1.2 V
VO = 1.8 V
90
Efficiency − %
5
50
100
50
POWER DISSIPATION
vs
LOAD CURRENT
0
3
6
0
9
12
15
18
IO − Load Current − A
Figure 7.
0
3
6
9
12
15
18
IO − Load Current − A
IO − Load Current − A
Figure 8.
Figure 9.
TEMPERATURE DERATING
vs
OUTPUT CURRENT
TA− Ambient Temperature − 5 C
90
80
400 LFM
70
200 LFM
100 LFM
60
Nat Conv
50
40
30
20
VO = ≤1.8 V
(See Note B)
0
3
6
9
12
15
18
IO − Load Current − A
Figure 10.
(3)
(4)
The electrical characteristic data has been developed from actual products tested at 25°C. This data is considered typical for the
converter. Applies to Figure 7, Figure 8, and Figure 9.
The temperature derating curves represent the conditions at which internal components are at or below the manufacturer's maximum
operating temperatures. Derating limits apply to modules soldered directly to a 4 inch × 4 inch double-sided PCB with 1oz. copper. For
surface mount products (AS and AZ suffix), multiple vias (plated through holes) are required to add thermal paths around the power
pins. Please refer to the mechanical specification for more information. Applies to Figure 10.
7
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
DEVICE INFORMATION
TERMINAL FUNCTIONS
TERMINAL
NAME
DESCRIPTION
NO.
VI
2
The positive input voltage power node to the module, which is referenced to common GND.
VO
6
The regulated positive power output with respect to the GND node.
GND
1, 7
This is the common ground connection for the Vin and Vout power connections. It is also the 0 VDC reference for the
control inputs.
Inhibit
3
The Inhibit pin is an open-collector/drain negative logic input that is referenced to GND. Applying a lowlevel ground
signal to this input disables the module’s output and turns off the output voltage. When the Inhibit control is active, the
input current drawn by the regulator is significantly reduced. If the inhibit feature is not used, the control pin should be
left open-circuit. The module will then produce an output whenever a valid input source is applied.
VO
Adjust
4
A 1% resistor must be connected directly between this pin and GND (pin 7) to set the output voltage of the module
higher than its lowest value. The temperature stability of the resistor should be 100 ppm/°C (or better). The set point
range is 1.2 V to 5.5 V for W-suffix devices, and 0.8 V to 1.8 V for L-suffix devices. The resistor value required for a
given output voltage may be calculated using a formula. If left open circuit, the module output voltage will default to its
lowest value. For further information on output voltage adjustment consult the related application note.
The specification table gives the preferred resistor values for a number of standard output voltages.
VO
Sense
Track
5
8
The sense input allows the regulation circuit to compensate for voltage drop between the module and the load. For
optimal voltage accuracy Vo Sense should be connected to Vout. It can also be left disconnected.
This is an analog control input that enables the output voltage to follow an external voltage. This pin becomes active
typically 20 ms after the input voltage has been applied, and allows direct control of the output voltage from 0 V up to
the nominal set-point voltage. Within this range the output will follow the voltage at the Track pin on a volt-for-volt basis.
When the control voltage is raised above this range, the module regulates at its set-point voltage. The feature allows
the output voltage to rise simultaneously with other modules powered from the same input bus. If unused this input
should be connected to Vin.
NOTE: Due to the under-voltage lockout feature, the output of the module cannot follow its own input voltage during
power up. For more information, consult the related application note.
Margin
Down
9
When this input is asserted to GND, the output voltage is decreased by 5% from the nominal. The input requires an
open-collector (open-drain) interface. It is not TTL compatible. A lower percent change can be accomodated with a
series resistor. For further information, consult the related application note.
Margin
Up
10
When this input is asserted to GND, the output voltage is increased by 5%. The input requires an open-collector
(open-drain) interface. It is not TTL compatible. The percent change can be reduced with a series resistor. For further
information, consult the related application note.
10 9
8
1
7
PTHXX020
(Top View)
2
6
3
8
4
5
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
APPLICATION INFORMATION
Capacitor Recommendations for the PTH12020 Series of Power Modules
Input Capacitor
The recommended input capacitance is determined by the 560 µF minimum capacitance and 800 mArms
minimum ripple current rating.
Ripple current, less than 100 mΩ equivalent series resistance (ESR), and temperature are major considerations
when selecting input capacitors. Unlike polymer-tantalum capacitors, regular tantalum capacitors are not
recommended for the input bus. These capacitors require a recommended minimum voltage rating of
2 × ~ (maximum DC voltage + AC ripple). This is standard practice to ensure reliability. There were no tantalum
capacitors, with sufficient voltage rating, found to meet this requirement. When the operating temperature is
below 0°C, the ESR of aluminum electrolytic capacitors increases. For these applications Os-Con,
polymer-tantalum, and polymer-aluminum types should be considered.
Adding a 10-µF ceramic capacitor to the input will reduce the ripple current reflected into the input source.
Output Capacitors (Optional)
For applications with load transients, the regulator response will benefit from external output capacitance. The
recommended output capacitance of 330 µF will allow the module to meet its transient response specification
(see product data sheet). For most applications, a high quality computer-grade aluminum electrolytic capacitor is
adequate. These capacitors provide decoupling over the frequency range, 2 kHz to 150 kHz, and are suitable
when ambient temperatures are above 0°C. For operation below 0°C, tantalum, ceramic, or Os-Con type
capacitors are recommended. When using one or more non-ceramic capacitors, the calculated equivalent ESR
should be no lower than 4 mΩ (7 mΩ using the manufacturer's maximum ESR for a single capacitor). A list of
preferred low-ESR type capacitors are identified in Table 1.
Ceramic Capacitor
Above 150 kHz the performance of aluminum electrolytic capacitors is less effective. Multilayer ceramic
capacitors have very low ESR and a resonant frequency higher than the bandwidth of the regulator. They can be
used to reduce the reflected ripple current at the input as well as improve the transient response of the output.
When used on the output their combined ESR is not critical as long as the total value of ceramic capacitance
does not exceed 300 µF. Also, to prevent the formation of local resonances, do not place more than five identical
ceramic capacitors in parallel with values of 10 µF or greater.
Tantalum Capacitors
Tantalum type capacitors can only be used on the output bus, and are recommended for applications where the
ambient operating temperature can be less than 0°C. The AVX TPS, Sprague 593D/594/595 and Kemet
T495/T510 capacitor series are suggested over many other tantalum types due to their higher rated surge, power
dissipation, and ripple current capability. As a caution many general purpose tantalum capacitors have
considerably higher ESR, reduced power dissipation and lower ripple current capability. These capacitors are
also less reliable as they have reduced power dissipation and surge current ratings. Tantalum capacitors that
have no stated ESR or surge current rating are not recommended for power applications.
When specifying Os-con and polymer tantalum capacitors for the output, the minimum ESR limit will be
encountered well before the maximum capacitance value is reached.
Capacitor Table
Table 1 identifies the characteristics of capacitors from a number of vendors with acceptable ESR and ripple
current (rms) ratings. The recommended 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 (at 100 kHz) are critical
parameters necessary to insure both optimum regulator performance and long capacitor life.
9
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
APPLICATION INFORMATION (continued)
Table 1. Input/Output Capacitors (1)
Capacitor Characteristics
CapacitorVendor,
Type/Series (Style)
Quantity
Max Ripple
Current at
85°C (Irms)
Physical Size
(mm)
Input
Bus
Optional
Output
Bus
Vendor
Part Number
Working
Voltage
Value
(µF)
Max ESR
at 100 kHz
Panasonic, Aluminum
25 V
330
0.090 Ω
775 mA
10×12.5
2
1
FC (Radial)
25 V
560
0.065 Ω
1205 mA
12.5×15
1
1
EEUFC1E561S
FK (SMD)
25 V
1,000
0.060 Ω
1100 mA
12.5×13.5
1
1
EEVFK1E102Q
FK (SMD)
35 V
680
0.060 Ω
1100 mA
12.5×13.5
1
1
EEVFK1V681Q
LXZ, Aluminum (Radial)
16
330
0.090 Ω
760 mA
10×12.5
2
1
LXZ25VB331M10X12LL
LXZ, Aluminum (Radial)
25
680
0.068 Ω
1050 mA
10×16
1
1
LXZ16VB681M10X16LL
PS, Poly-Aluminum (Radial)
16
330
0.014 Ω
5060 mA
10×12.5
2
≤2
16PS330MJ12
PXA, Poly-Aluminum (SMD)
16
330
0.014 Ω
5050 mA
10×12.2
2
≤2
PXA16VC331MJ12TP
Nichicon, Aluminum (PM)
25 V
560
0.060 Ω
1060 mA
12.5×15
1
1
UPM1E561MHH6
HD (Radial)
16 V
680
0.038 Ω
1430 mA
10×16
1
1
UHD1C681MHR
PM (Radial)
35 V
560
0.048 Ω
1360 mA
16×15
1
1
UPM1V561MHH6
6.3 V
180
0.005 Ω
4000 mA
7.3×4.3×4.2
N/R (2)
≤1
EEFSE0J181R (Vo≤5.1V)
EEUFC1E331
United Chemi-Con
Panasonic, Poly-Aluminum
S/SE (SMD)
Samyo
TP, Psocap
10 V
330
0.025 Ω
3000 mA
7.3L×5.7W
N/R (2)
≤4
10TPE330M
SEQP, Os-Con
16 V
330
0.018 Ω
>3500 mA
10×10.5
2 (3)
≤3
16SP270M
SVP, Os-Con (SMD)
16 V
330
0.016 Ω
4700 mA
11×12
2
≤3
16SVP330M
AVX, Tantalum, Series III
10 V
470
0.045 Ω
>1723 mA
N/R (2)
≤5
TPSE477M010R0045 (Vo≤5.1V)
TPS (SMD)
10 V
330
0.045 Ω
>1723 mA
N/R (2)
≤5
TPSE337M010R0045 (Vo≤5.1V)
7.3L×5.7W×4.1H
Kemet (SMD)
N/R (2)
≤5
T520X337M010AS
N/R (2)
≤1
T530X337M010ASE010
N/R (2)
≤1
T530X477M006ASE010(Vo≤5.1V)
7.2L×6W×4.1H
N/R (2)
≤5
595D477X0010R2T(Vo≤5.1V)
9740 mA
16×25
2
≤2
94SA108X0016HBP
0.017Ω
4580 mA
10 × 12,7
2
≤2
94SVP337X0016F12
10
0.002 Ω
—
1210 case
1 (4)
≤5
C1210C106M4PAC
6.3 V
47
0.002 Ω
3225 mm
N/R (2)
≤5
C1210C476K9PAC
6.3 V
100
0.002 Ω
1210 case
N/R (2)
≤3
GRM32ER60J107M
16 V
47
3225 mm
1 (4)
≤5
GRM32ER61C476K
16 V
22
1 (4)
≤5
GRM32ER61C226K
16 V
10
1 (4)
≤5
GRM32DR61C106K
6.3 V
100
1210 case
N/R (2)
≤3
C3225X5R0J107MT
6.3 V
47
3225 mm
N/R (2)
≤5
C3225X5R0J476MT
16 V
22
1 (4)
≤5
C3225X5R1C226MT
16 V
10
1 (4)
≤5
C3225X5R1C106MT
T520, Poly-Tant
10 V
330
0.040 Ω
1800 mA
T530, Poly-Tant/Organic
10 V
330
0.010 Ω
>3800 mA
6.3 V
470
0.010 Ω
4200 mA
595D, Tantalum (SMD)
10 V
470
0.100 Ω
1440 mA
94SA, Os-con (Radial)
16 V
1,000
0.015 Ω
94SVP
16V
330
Kemet, Ceramic X5R (SMD)
16 V
43W ×7.3L
×4.0H
Vishay-Sprague
Murata, Ceramic X5R (SMD)
TDK, Ceramic X5R (SMD)
(1)
(2)
(3)
(4)
10
0.002 Ω
—
—
Capacitor Supplier Verification
1.Please verify availability of capacitors identified in this table. Capacitor suppliers may recommend alternative part numbers because of
limited availability or obsolete products. In some instances, the capacitor product life cycle may be in decline and have short-term
consideration for obsolescence.
RoHS, Lead-free and Material Details
2.Please consult capacitor suppliers regarding material composition, RoHS status, lead-free status, and manufacturing process
requirements. Component designators or part number deviations can occur when material composition or soldering requirements are
updated.
N/R – Not recommended. The voltage rating does not meet the minimum operating limits.
Total capacitance of 540 µF is acceptable based on the combined ripple current rating.
Ceramic capacitors may be used to complement electrolytic types at the input to further reduce high-frequency ripple current.
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
Designing for Very Fast Load Transients
The transient response of the DC/DC converter has been characterized using a load transient with a di/dt of
1 A/µs. The typical voltage deviation for this load transient is given in the data sheet specification table using the
optional value of output capacitance. As the di/dt of a transient is increased, the response of a converter's
regulation circuit ultimately depends on its output capacitor decoupling network. This is an inherent limitation with
any DC/DC converter once the speed of the transient exceeds its bandwidth capability. If the target application
specifies a higher di/dt or lower voltage deviation, the requirement can only be met with additional output
capacitor decoupling. In these cases special attention must be paid to the type, value and ESR of the capacitors
selected.
If the transient performance requirements exceed that specified in the data sheet, or the total amount of load
capacitance is above 3000 µF, the selection of output capacitors becomes more important.
Adjusting the Output Voltage of the PTH12020x Series of Wide-Output Adjust Power Modules
The VoAdjust control (pin 4) sets the output voltage of the PTH12020 product. The adjustment range is from
1.2 V to 5.5 V for the W-suffix modules, and 0.8 V to 1.8 V for L-suffix modules. The adjustment method requires
the addition of a single external resistor, Rset, that must be connected directly between the VoAdjust and GND
pins 1. Table 2 gives the preferred value of the external resistor for a number of standard voltages, along with
the actual output voltage that this resistance value provides. Figure 11 shows the placement of the required
resistor.
Table 2. Preferred Values of Rset for Standard Output Voltages
PTH12020W
Vout
(Req'd)
Rset
PTH12020L
Vout
(Actual)
Rset
Vout
(Actual)
5V
280 Ω
5.009 V
N/A
N/A
3.3 V
2.0 kΩ
3.294 V
N/A
N/A
2.5 V
4.32 kΩ
2.503 V
N/A
N/A
2V
8.06 kΩ
2.010 V
N/A
N/A
1.8 V
11.5 kΩ
1.801 V
130 Ω
1.800 V
1.5 V
24.3 kΩ
1.506 V
3.57 kΩ
1.499 V
1.2 V
Open
1.200 V
12.1 kΩ
1.201 V
1.1 V
N/A
N/A
18.7 kΩ
1.101 V
1.0 V
N/A
N/A
32.4 kΩ
0.999 V
0.9 V
N/A
N/A
71.5 kΩ
0.901 V
0.8 V
N/A
N/A
Open
0.800 V
For other output voltages the value of the required resistor can either be calculated, or simply selected from the
range of values given in Table 4. The equation below may be used for calculating the adjust resistor value.
Select the appropriate value for the parameters, Rs and Vmin, from Table 3.
0.8 V
R set + 10 kW
* R s kW
V out * V
min
(1)
Table 3. Adjust Formula Parameters
Pt. No.
PTH12020W
PTH12020L
Vmin
1.2 V
0.8 V
Vmax
5.5 V
1.8 V
Rs
1.82 kΩ
7.87 kΩ
11
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
VO Sense
10
9
8
5
VO Sense
VOUT
PTH12020x
VOUT
VO Adj
GND
7
RSET, 1%
COUT
330 mF
+
GN D
14
6
GND
(1)
A 0.05-W rated resistor may be used. The tolerance should be 1%, with temperature stability of 100 ppm/°C (or
better). Place the resistor as close to the regulator as possible. Connect the resistor directly between pins 4 and 7
using dedicated PCB traces.
(2)
Never connect capacitors from VoAdjust to either GND or Vout. Any capacitance added to the VoAdjust pin will affect
the stability of the regulator.
Figure 11. Vo Adjust Resistor Placement
Table 4. Output Voltage Set-Point Resistor Values
PTH12020W
12
PTH12020L
VOUT
RSET
VOUT
RSET
VOUT
RSET
1.200
Open
2.70
3.51 kΩ
0.800
Open
1.225
318.0 kΩ
2.75
3.34 kΩ
0.825
312.0 kΩ
1.250
158.0 kΩ
2.80
3.18 kΩ
0.850
152.0 kΩ
1.275
105.0 kΩ
2.85
3.03 kΩ
0.875
98.8 kΩ
1.300
78.2 kΩ
2.90
2.89 kΩ
0.900
72.1 kΩ
1.325
67.2 kΩ
2.95
2.75 kΩ
0.925
56.1 kΩ
1.350
51.5 kΩ
3.00
2.62 kΩ
0.950
45.5 kΩ
1.375
43.9 kΩ
3.05
2.50 kΩ
0.975
37.8 kΩ
1.400
38.2 kΩ
3.10
2.39 kΩ
1.000
32.1 kΩ
1.425
33.7 kΩ
3.15
2.28 kΩ
1.025
27.7 kΩ
1.450
30.2 kΩ
3.20
2.18 kΩ
1.050
24.1 kΩ
1.475
27.3 kΩ
3.25
2.08 kΩ
1.075
21.2 kΩ
1.50
24.8 kΩ
3.30
1.99 kΩ
1.100
18.8 kΩ
1.55
21.0 kΩ
3.35
1.90 kΩ
1.125
16.7 kΩ
1.60
18.2 kΩ
3.40
1.82 kΩ
1.150
15.0 kΩ
1.65
16.0 kΩ
3.50
1.66 kΩ
1.175
13.5 kΩ
1.70
14.2 kΩ
3.60
1.51 kΩ
1.200
12.1 kΩ
1.75
12.7 kΩ
3.70
1.38 kΩ
1.225
11.0 kΩ
1.80
11.5 kΩ
3.80
1.26 kΩ
1.250
9.91 kΩ
1.85
10.5 kΩ
3.90
1.14 kΩ
1.275
8.97 kΩ
1.90
9.61 kΩ
4.00
1.04 kΩ
1.300
8.13 kΩ
1.95
8.85 kΩ
4.10
939 Ω
1.325
7.37 kΩ
2.00
8.18 kΩ
4.20
847 Ω
1.350
6.68 kΩ
2.05
7.59 kΩ
4.30
761 Ω
1.375
6.04 kΩ
2.10
7.07 kΩ
4.40
680 Ω
1.400
5.46 kΩ
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
Table 4. Output Voltage Set-Point Resistor Values (continued)
PTH12020W
PTH12020L
VOUT
RSET
VOUT
RSET
VOUT
RSET
2.15
6.60 kΩ
4.50
604 Ω
1.425
4.93 kΩ
2.20
6.18 kΩ
4.60
533 Ω
1.450
4.44 kΩ
2.25
5.80 kΩ
4.70
466 Ω
1.475
3.98 kΩ
2.30
5.45 kΩ
4.80
402 Ω
1.50
3.56 kΩ
2.35
5.14 kΩ
4.90
342 Ω
1.55
2.8 kΩ
2.40
4.85 kΩ
5.00
285 Ω
1.60
2.13 kΩ
2.45
4.58 kΩ
5.10
231 Ω
1.65
1.54 kΩ
2.50
4.33 kΩ
5.20
180 Ω
1.70
1.02 kΩ
2.55
4.11 kΩ
5.30
131 Ω
1.75
551 Ω
2.60
3.89 kΩ
5.40
85 Ω
1.80
130 Ω
2.65
3.70 kΩ
5.50
41 Ω
Features of the PTH Family of Non-Isolated Wide Output Adjust Power Modules
POLA™ Compatibility
The PTH/PTV family of non-isolated, wide-output adjustable power modules from Texas Instruments are
optimized for applications that require a flexible, high performance module that is small in size. Each of these
products are POLA™ compatible. POLA-compatible products are produced by a number of manufacturers, and
offer customers advanced, non-isolated modules with the same footprint and form factor. POLA parts are also
assured to be interoperable, thereby providing customers with true second-source availability.
From the basic, Just Plug it In functionality of the 6-A modules, to the 30-A rated feature-rich PTHxx030, these
products were designed to be very flexible, yet simple to use. The features vary with each product. Table 5
provides a quick reference to the features by product series and input bus voltage.
Table 5. Operating Features by Series and Input Bus Voltage
Series
PTHxx050
PTHxx060
PTHxx010
PTVxx010
PTHxx020
PTVxx020
PTHxx030
IOUT
Adjust
(Trim)
On/Off
Inhibit
OverCurrent
Pre-Bias
Startup
AutoTrack™
3.3 V
6A
•
•
•
•
•
5V
6A
•
•
•
•
•
12 V
6A
•
•
•
•
•
3.3 V/5 V
10 A
•
•
•
•
Input Bus
Margin
Up/Down
Output
Sense
•
•
•
12 V
8A
•
•
•
•
•
•
•
3.3 V/5 V
15 A
•
•
•
•
•
•
•
12 V
12 A
•
•
•
•
•
•
•
Thermal
Shutdown
5V
8A
•
•
•
•
•
12 V
8A
•
•
•
•
•
3.3 V/5 V
22 A
•
•
•
•
•
•
•
•
12 V
18 A
•
•
•
•
•
•
•
•
5V
18 A
•
•
•
•
•
•
•
12 V
16 A
•
•
•
•
•
•
•
3.3 V/5 V
30 A
•
•
•
•
•
•
•
•
12 V
26 A
•
•
•
•
•
•
•
•
•
•
13
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
For simple point-of-use applications, the PTH12050 (6 A) provides operating features such as an on/off inhibit,
output voltage trim, pre-bias start-up and over-current protection. The PTH12060 (10 A), and PTH12010 (12 A)
include an output voltage sense, and margin up/down controls. Then the higher output current, PTH12020 (18 A)
and PTH12030 (26 A) products incorporate overtemperature shutdown protection.
The PTV12010 and PTV12020 are similar parts offered in a vertical, single in-line pin (SIP) profile, at slightly
lower current ratings.
All of the products referenced in Table 5 include Auto- Track™. This feature was specifically designed to simplify
the task of sequencing the supply voltages in a power system. This and other features are described in the
following sections.
Soft-Start Power UP
The Auto-Track feature allows the power-up of multiple PTH modules to be directly controlled from the Track pin.
However in a stand-alone configuration, or when the Auto-Track feature is not being used, the Track pin should
be directly connected to the input voltage, Vin (see Figure 12).
8
10 9
Up Dn Track
2
VIN
PTH12020W
Inhibit
3
GND
1
CIN
1,000 mF
VO
3.3 V
6
Adjust
7
4
R SET
, 2 kW
+
12 V
5
Sense
0.1 W, 1 %
COUT
330 mF
+
GND
GND
Figure 12. Power-Up Application Circuit
When the Track pin is connected to the input voltage the Auto-Track function is permanently disengaged. This
allows the module to power up entirely under the control of its internal soft-start circuitry. When power up is
under soft-start control, the output voltage rises to the set-point at a quicker and more linear rate.
Vin (5 V/Div)
Vo (1 V/Div)
Iin (5 A/Div)
HORIZ SCALE 5 ms/Div
Figure 13. Power-Up Waveforms
From the moment a valid input voltage is applied, the soft-start control introduces a short time delay
(typically 8 ms–15 ms) before allowing the output voltage to rise. The output then progressively rises to the
module’s setpoint voltage. Figure 13 shows the soft-start power-up characteristic of the 18-A output product
(PTH12020W), operating from a 12-V input bus and configured for a 3.3-V output. The waveforms were
measured with a 5-A resistive load and the Auto-Track feature disabled. The initial rise in input current when the
input voltage first starts to rise is the charge current drawn by the input capacitors. Power-up is complete within
25 ms.
14
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
Over-Current Protection
For protection against load faults, all modules incorporate output over-current protection. Applying a load that
exceeds the regulator's over-current threshold will cause the regulated output to shut down. Following shutdown
a module will periodically attempt to recover by initiating a soft-start power-up. This is described as a hiccup
mode of operation, whereby the module continues in a cycle of successive shutdown and power up until the load
fault is removed. During this period, the average current flowing into the fault is significantly reduced. Once the
fault is removed, the module automatically recovers and returns to normal operation.
Over-Temperature Protection (OTP)
The PTH12020W and PTH12030W products have overtemperature protection. These products have an on-board
temperature sensor that protects the module's internal circuitry against excessively high temperatures. A rise in
the internal temperature may be the result of a drop in airflow, or a high ambient temperature. If the internal
temperature exceeds the OTP threshold, the module's Inhibit control is internally pulled low. This turns the output
off. The output voltage will drop as the external output capacitors are discharged by the load circuit. The recovery
is automatic, and begins with a soft-start power up. It occurs when the the sensed temperature decreases by
about 10°C below the trip point.
Note: The over-temperature protection is a last resort mechanism to prevent thermal stress to the regulator.
Operation at or close to the thermal shutdown temperature is not recommended and will reduce the
long-term reliability of the module. Always operate the regulator within the specified Safe Operating Area
(SOA) limits for the worst-case conditions of ambient temperature and airflow.
Output On/Off Inhibit
For applications requiring output voltage on/off control, each series of the PTH family incorporates an output
Inhibit control pin. The inhibit feature can be used wherever there is a requirement for the output voltage from the
regulator to be turned off.
The power modules function normally when the Inhibit pin is left open-circuit, providing a regulated output
whenever a valid source voltage is connected to VI with respect to GND.
Figure 14 shows the typical application of the inhibit function. Note the discrete transistor (Q1). The Inhibit input
has its own internal pull-up to a potential of 5 V to 13.2 V (see footnotes to specification table). The input is not
compatible with TTL logic devices. An open-collector (or open-drain) discrete transistor is recommended for
control.
VOSense
VIN
2
+
1 =Inhibit
Q1
BSS138
8
5
7
VOUT
6
PTH12060W
3 1
CIN
560 mF
9
4
RSET
2 kW
1%
0.1 W
COUT
330 mF
+
10
L
O
A
D
GND
GND
Figure 14. Inhibit Control Circuit
Turning Q1 on applies a low voltage to the Inhibit control pin and disables the output of the module. If Q1 is then
turned off, the module will execute a soft-start power-up sequence. A regulated output voltage is produced within
25 msec. Figure 15 shows the typical rise in both the output voltage and input current, following the turn-off of
Q1. The turn off of Q1 corresponds to the rise in the waveform, Q1 Vds. The waveforms were measured with a 5-A
constant current load.
15
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
Q1Vds (5 V/Div)
Vo (2 V/Div)
Iin (2 A/Div)
HORIZ SCALE: 10 ms/Div
Figure 15. Power-Up from Inhibit Control
Auto-Track™ Function
The Auto-Track function is unique to the PTH/PTV family, and is available with all POLA products. Auto-Track
was designed to simplify the amount of circuitry required to make the output voltage from each module power up
and power down in sequence. The sequencing of two or more supply voltages during power up is a common
requirement for complex mixed-signal applications that use dual-voltage VLSI ICs such as the TMS320™ DSP
family, microprocessors, and ASICs.
How Auto-Track™ Works
Auto-Track works by forcing the module output voltage to follow a voltage presented at the Track control pin (1).
This control range is limited to between 0 V and the module set-point voltage. Once the track-pin voltage is
raised above the set-point voltage, the module output remains at its set-point (2). As an example, if the Track pin
of a 2.5-V regulator is at 1 V, the regulated output is 1 V. If the voltage at the Track pin rises to 3 V, the regulated
output does not go higher than 2.5 V.
When under Auto-Track control, the regulated output from the module follows the voltage at its Track pin on a
volt-for-volt basis. By connecting the Track pin of a number of these modules together, the output voltages follow
a common signal during power up and power down. The control signal can be an externally generated master
ramp waveform, or the output voltage from another power supply circuit (3). For convenience, the Track input
incorporates an internal RC-charge circuit. This operates off the module input voltage to produce a suitable rising
waveform at power up.
16
www.ti.com
PTH12020W/L
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
Typical Application
The basic implementation of Auto-Track allows for simultaneous voltage sequencing of a number of Auto-Track
compliant modules. Connecting the Track inputs of two or more modules forces their track input to follow the
same collective RC-ramp waveform, and allows their power-up sequence to be coordinated from a common
Track control signal. This can be an open-collector (or open-drain) device, such as a power-up reset voltage
supervisor IC. See U3 in Figure 16.
To coordinate a power-up sequence, the Track control must first be pulled to ground potential. This should be
done at or before input power is applied to the modules. The ground signal should be maintained for at least
40 ms after input power has been applied. This brief period gives the modules time to complete their internal
soft-start initialization (4), enabling them to produce an output voltage. A low-cost supply voltage supervisor IC,
that includes a built-in time delay, is an ideal component for automatically controlling the Track inputs at power
up.
Figure 16 shows how the TL7712A supply voltage supervisor IC (U3) can be used to coordinate the sequenced
power up of two 12-V input Auto-Track modules. The output of the TL7712A supervisor becomes active above
an input voltage of 3.6 V, enabling it to assert a ground signal to the common track control well before the input
voltage has reached the module's undervoltage lockout threshold. The ground signal is maintained until
approximately 43 ms after the input voltage has risen above U3's voltage threshold, which is 10.95 V. The 43-ms
time period is controlled by the capacitor C3. The value of 3.3 µF provides sufficient time delay for the modules
to complete their internal soft-start initialization. The output voltage of each module remains at zero until the track
control voltage is allowed to rise. When U3 removes the ground signal, the track control voltage automatically
rises. This causes the output voltage of each module to rise simultaneously with the other modules, until each
reaches its respective set-point voltage.
Figure 17 shows the output voltage waveforms from the circuit of Figure 16 after input voltage is applied to the
circuit. The waveforms, VO1 and VO2, represent the output voltages from the two power modules, U1 (3.3 V) and
U2 (1.8 V), respectively. VTRK, VO1, and VO2 are shown rising together to produce the desired simultaneous
power-up characteristic.
The same circuit also provides a power-down sequence. When the input voltage falls below U3's voltage
threshold, the ground signal is re-applied to the common track control. This pulls the track inputs to zero volts,
forcing the output of each module to follow, as shown in Figure 18. In order for a simultaneous power-down to
occur, the track inputs must be pulled low before the input voltage has fallen below the modules' undervoltage
lockout. This is an important constraint. Once the modules recognize that a valid input voltage is no longer
present, their outputs can no longer follow the voltage applied at their track input. During a power-down
sequence, the fall in the output voltage from the modules is limited by the maximum output capacitance and the
Auto-Track slew rate. If the Track pin is pulled low at a slew rate greater than 1 V/ms, the discharge of the output
capacitors will induce large currents which could exceed the peak current rating of the module. This will result in
a reduction in the maximum allowable output capacitance as listed in the Electrical Characteristics table. When
controlling the Track pin of the PTH12020W using a voltage supervisor IC, the slew rate is increased, therefore
COmax is reduced to 6600 µF.
Notes on Use of Auto-Track™
1. The Track pin voltage must be allowed to rise above the module set-point voltage before the module
regulates at its adjusted set-point voltage.
2. The Auto-Track function tracks almost any voltage ramp during power up, and is compatible with ramp
speeds of up to 1 V/ms.
3. The absolute maximum voltage that may be applied to the Track pin is the input voltage VI.
4. The module cannot follow a voltage at its track control input until it has completed its soft-start initialization.
This takes about 40 ms from the time that a valid voltage has been applied to its input. During this period, it
is recommended that the Track pin be held at ground potential.
5. The Auto-Track function is disabled by connecting the Track pin to the input voltage (VI). When Auto-Track is
disabled, the output voltage rises at a quicker and more linear rate after input power has been applied.
17
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
2
U1
Track
VI = 12 V
3
+
VI
Inhibit
GND
4
1
Vo 1 = 3.3 V
6
VO
PTH12050W
Adjust
5
CI1
+
RSET1
CO1
2.0 kΩ
U3
7
2
1
3
8
VCC
SENSE
RESET
5
RTRK #
RESIN
TL7712A
REF
RESET
50 Ω
0.1 µF
9
Up Dn
8
5
Track
Sense
CT
2
GND
CREF
10
U2
6
4
CT
VO
Vo 2 = 1.8 V
6
RRST
10 kΩ
3.3 µF
PTH12060W
VI
Inhibit
+
# RTRK = 100 Ω / N
N = Number of Track pins connected together
3
C I2
Adjust
GND
1
7
4
RSET2
+
CO2
11.5 kΩ
Figure 16. Sequenced Power Up and Power Down Using Auto-Track
VTRK (1 V/div)
VTRK (1 V/div)
V01 (1 V/div)
V01 (1 V/div)
V02 (1 V/div)
V02 (1 V/div)
t − Time − 20 ms/div
Figure 17. Simultaneous Power Up
With Auto-Track Control
t − Time − 400 µs/div
Figure 18. Simultaneous Power
Down With Auto-Track Control
Margin Up/Down Controls
The PTH12060, PTH12010, PTH12020, and PTH12030 products incorporate Margin Up and Margin Down
control inputs. These controls allow the output voltage to be momentarily adjusted1, either up or down, by a
nominal 5%. This provides a convenient method for dynamically testing the operation of the load circuit over its
supply margin or range. It can also be used to verify the function of supply voltage supervisors. The ±5% change
is applied to the adjusted output voltage, as set by the external resistor, Rset at the VoAdjust pin.
18
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
The 5% adjustment is made by pulling the appropriate margin control input directly to the GND terminal2. A
low-leakage open-drain device, such as an n-channel MOSFET or p-channel JFET is recommended for this
purpose3. Adjustments of less than 5% can also be accommodated by adding series resistors to the control
inputs. The value of the resistor can be selected from Table 6, or calculated using the formula in Equation 2.
NOTES:
1. The Margin Up and Margin Dn controls were not intended to be activated simultaneously. If they are their
affects on the output voltage may not completely cancel, resulting in the possibility of a slightly higher error in
the output voltage set point.
2. The ground reference should be a direct connection to the module GND at pin 7 (pin 1 for the PTHxx050).
This will produce a more accurate adjustment at the load circuit terminals. The transistors Q1 and Q2 should
be located close to the regulator.
3. The Margin Up and Margin Dn control inputs are not compatible with devices that source voltage. This
includes TTL logic. These are analog inputs and should only be controlled with a true open-drain device
(preferably a discrete MOSFET transistor). The device selected should have low off-state leakage current.
Each input sources 8 µA when grounded, and has an open-circuit voltage of 0.8 V.
Up/Down Adjust Resistance Calculation
To reduce the margin adjustment to a value less than 5%, series resistors are required (See RD and RU in
Figure 19). For the same amount of adjustment, the resistor value calculated for RU and RD will be the same.
The formula is shown in Equation 2.
R or R + 499 * 99.8 kW
U
D
D%
(2)
Where ∆% = The desired amount of margin adjust in percent.
Table 6. Margin Up/Down Resistor Values
% Adjust
RU/RD
5
0.0 kΩ
4
24.9 kΩ
3
66.5 kΩ
2
150.0 kΩ
1
397.0 kΩ
1
VIN
2
10
Cin
MargDn
MargUp
+
8
PT H12010W
( T op V iew)
3
RD
9
4
7
+VO
0V
+VOUT
6
5
RU
RSET
0.1 W, 1 %
Q1
Cout
+
L
O
A
D
Q2
GND
GND
Figure 19. Margin Up/Down Application Schematic
19
PTH12020W/L
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
www.ti.com
Pre-Bias Startup Capability
The capability to start up into an output pre-bias condition is now available to all the 12-V input, PTH series of
power modules. (Note that this is a feature enhancement for the many of the W-suffix products)1.
A pre-bias startup condition occurs as a result of an external voltage being present at the output of a power
module prior to its output becoming active. This often occurs in complex digital systems when current from
another power source is backfed through a dual-supply logic component, such as an FPGA or ASIC. Another
path might be via clamp diodes, sometimes used as part of a dual-supply power-up sequencing arrangement. A
prebias can cause problems with power modules that incorporate synchronous rectifiers. This is because under
most operating conditions, such modules can sink as well as source output current. The 12-V input PTH modules
all incorporate synchronous rectifiers, but will not sink current during startup, or whenever the Inhibit pin is held
low. Startup includes an initial delay (approximately 8–15 ms), followed by the rise of the output voltage under
the control of the module's internal soft-start mechanism; see Figure 20.
Conditions for Pre-Bias Holdoff
In order for the module to allow an output pre-bias voltage to exist (and not sink current), certain conditions must
be maintained. The module holds off a pre-bias voltage when the Inhibit pin is held low, and whenver the output
is allowed to rise under soft-start control. Power up under soft-start control occurs upon the removal of the
ground signal to the Inhibit pin (with input voltage applied), or when input power is applied with Auto-Track
disabled2. To further ensure that the regulator does not sink output current, (even with a ground signal applied to
its Inhibit), the input voltage must always be greater than the applied pre-bias source. This condition must exist
throughout the power-up sequence3.
The soft-start period is complete when the output begins rising above the pre-bias voltage. Once it is complete
the module functions as normal, and will sink current if a voltage higher than the nominal regulation value is
applied to its output.
Note: If a pre-bias condition is not present, the soft-start period will be complete when the output voltage has
risen to either the set-point voltage, or the voltage applied at the module's Track control pin, whichever is
lowest. to its output.
20
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
Demonstration Circuit
Figure 21 shows the startup waveforms for the demonstration circuit shown in Figure 22. The initial rise in Vo2 is
the pre-bias voltage, which is passed from the VCCIO to the VCORE voltage rail through the ASIC. Note that the
output current from the PTH12010L module (Io2) is negligible until its output voltage rises above the applied
pre-bias.
Vin (5 V/Div)
Vo1 (1 V/Div)
Vo (1 V/Div)
Vo2 (1 V/Div)
Io2 (5 A/Div)
Startup
Period
HORIZ SCALE 5 ms/Div
Figure 20. PTH12020W Startup
HORIZ SCALE: 10 ms/Div
Figure 21. Pre-Bias Startup Waveforms
NOTES:
1. Output pre-bias holdoff is an inherent feature to all PTH120x0L and PTV120x0W/L modules. It has now been
incorporated into all modules (including W-suffix modules with part numbers of the form PTH120x0W), with a
production lot date code of 0423 or later.
2. The pre-bias start-up feature is not compatible with Auto-Track. If the rise in the output is limited by the
voltage applied to the Track control pin, the output will sink current during the period that the track control
voltage is below that of the back-feeding source. For this reason, it is recommended that Auto-Track be
disabled when not being used. This is accomplished by connecting the Track pin to the input voltage, Vin.
This raises the Track pin voltage well above the set-point voltage prior to the module’s start up, thereby
defeating the Auto-Track feature.
3. To further ensure that the regulator's output does not sink current when power is first applied (even with a
ground signal applied to the Inhibit control pin), the input voltage must always be greater than the applied
pre-bias source. This condition must exist throughout the power-up sequence of the power system.
21
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
10 98
Up
V IN= 12 V
2
5
Dn Tra ck
VIN
PTH12020W
Inhibit
3
GND
1
7
+ C1
330 mF
10 98
2
TL7702B
8
VCC
SENSE
5
RESET
2
RESIN
1
6
REF
RESET
3
CT
GND
4
C6
R5
0.68 mF
10 kW
VIN
7
R4
100 kW
C5
0.1 mF
PTH12010L
Inhibit
3
6
VO
Adjust
4
R1
2 kW
Vo 1 = 3. 3 V
+
C2
330 mF
5
Tra ck
R3
11 kW
Sense
GND
1
7
Sense
VO
6
Vadj
4
Vo 2 = 1.8 V
+
Io2
R2
130 W
+ C3
330 mF
VC ORE
+ C4
330 mF
VC CI O
ASIC
Figure 22. Application Circuit Demonstrating Pre-Bias Startup
Remote Sense
Products with this feature incorporate an output voltage sense pin, Vo Sense. A remote sense improves the load
regulation performance of the module by allowing it to compensate for any IR voltage drop between its output
and the load. An IR drop is caused by the high output current flowing through the small amount of pin and trace
resistance.
To use this feature simply connect the Vo Sense pin to the Vout node, close to the load circuit (see data sheet
standard application). If a sense pin is left open-circuit, an internal low-value resistor (15-Ω or less) connected
between the pin and and the output node, ensures the output remains in regulation.
With the sense pin connected, the difference between the voltage measured directly between the Vout and GND
pins, and that measured from Vo Sense to GND, is the amount of IR drop being compensated by the regulator.
This should be limited to a maximum of 0.3 V.
Note: The remote sense feature is not designed to compensate for the forward drop of non-linear or
frequency dependent components that may be placed in series with the converter output. Examples include
OR-ing diodes, filter inductors, ferrite beads, and fuses. When these components are enclosed by the remote
sense connection they are effectively placed inside the regulation control loop, which can adversely affect the
stability of the regulator.
22
PTH12020W/L
www.ti.com
SLTS208E – MAY 2003 – REVISED OCTOBER 2005
TAPE AND REEL SPECIFICATIONS
TRAY SPECIFICATIONS
23
PACKAGE OPTION ADDENDUM
www.ti.com
26-Oct-2005
PACKAGING INFORMATION
Orderable Device
Status (1)
Package
Type
Package
Drawing
Pins Package Eco Plan (2)
Qty
PTH12020LAH
ACTIVE
DIP MOD
ULE
EUK
10
20
TBD
Call TI
Level-1-235C-UNLIM
PTH12020LAS
ACTIVE
DIP MOD
ULE
EUL
10
20
TBD
Call TI
Level-1-235C-UNLIM
PTH12020LAST
ACTIVE
DIP MOD
ULE
EUL
10
200
TBD
Call TI
Level-1-235C-UNLIM
PTH12020LAZ
ACTIVE
DIP MOD
ULE
EUL
10
20
Pb-Free
(RoHS)
Call TI
Level-3-260C-168 HR
PTH12020LAZT
ACTIVE
DIP MOD
ULE
EUL
10
200
Pb-Free
(RoHS)
Call TI
Level-3-260C-168 HR
PTH12020WAD
ACTIVE
DIP MOD
ULE
EUK
10
20
Pb-Free
(RoHS)
Call TI
Level-NC-NC-NC
PTH12020WAH
ACTIVE
DIP MOD
ULE
EUK
10
20
TBD
Call TI
Level-1-235C-UNLIM
PTH12020WAS
ACTIVE
DIP MOD
ULE
EUL
10
20
TBD
Call TI
Level-1-235C-UNLIM
PTH12020WAST
ACTIVE
DIP MOD
ULE
EUL
10
200
TBD
Call TI
Level-1-235C-UNLIM
PTH12020WAZ
ACTIVE
DIP MOD
ULE
EUL
10
20
Pb-Free
(RoHS)
Call TI
Level-3-260C-168 HR
PTH12020WAZT
ACTIVE
DIP MOD
ULE
EUL
10
200
Pb-Free
(RoHS)
Call TI
Level-3-260C-168 HR
Lead/Ball Finish
MSL Peak Temp (3)
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in
a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS) 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 1
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