Astec ATH12 6-a, 3.3-v input non-isolated wide-output adjust power module Datasheet

ATH06T033 Series —3.3-V Input
6-A, 3.3-V Input Non-Isolated
Wide-Output Adjust Power Module
REVISION 00 (01DEC2003)
Features
NOMINAL SIZE =
• Up to 6-A Output Current
• 3.3-V Input Voltage
• Wide-Output Voltage Adjust
(0.8 V to 2.5 V)
• Efficiencies up to 94 %
• 103 W/in³ Power Density
• On/Off Inhibit
• Pre-Bias Startup
• Under-Voltage Lockout
• Operating Temp: –40 to +85 °C
0.87 in x 0.5 in
(22,1 mm x 12,57 mm)
• Auto-Track™ Sequencing
• Output Over-Current Protection
(Non-Latching, Auto-Reset)
• IPC Lead Free 2
• Safety Agency Approvals (Pending)
UL 1950, CSA 22.2 950, &
EN60950
• Point-of-Load Alliance (POLA)
Compatible
Pin Configuration
ADVANCE INFORMATION
Description
The ATH06T033 series is one of the
smallest non-isolated power modules that
features Auto-Track™. Auto-Track™
simplifies supply voltage sequencing in
power systems by enabling modules to track
each other, or any other external voltage,
during power up and power down.
Although small in size (0.87 in × 0.5 in),
these modules are rated for up to 6 A of
output current, and are an ideal choice in
applications where space, performance,
and a power-up sequencing capability are
important attributes.
The product provides high-performance
step-down conversion from a 3.3-V input
bus voltage. The output voltage of the
ATH06T033 can be set to any voltage
over the range, 0.8 V to 2.5 V, using a
single resistor.
Other operating features include an
on/off inhibit, output voltage adjust (trim),
and output over-current protection. For
high efficiency these parts employ a
synchronous rectifier output stage, but a
pre-bias hold-off capability ensures that
the output will not sink current during
startup.
Target applications include telecom,
industrial, and general purpose circuits,
including low-power dual-voltage systems
that use a DSP, microprocessor, ASIC, or
FPGA.
Package options include both throughhole and surface mount configurations.
Pin
1
2
3
4
5
6
Function
GND
Track
Vin
Inhibit *
Vo Adjust
Vout
* Denotes negative logic:
Open
= Normal operation
Ground = Function active
™
Track
o
t
u
A
g
encin
u
q
e
S
Standard Application
Rset = Required to set the output voltage to a value
higher than 0.8 V. (See spec. table for values)
Cin = Required 100 µF
Co 1 = Optional 100 µF capacitor
Co 2 = Optional 10 µF ceramic capacitor for reduced
output ripple.
Track
1
2
VIN
3
PTH03050W
(Top View)
ATH06T033-9S
4
CIN
100 µF
(Required)
VOUT
6
5
RSET
1 %, 0.1 W
(Required)
Co1
100 µF
Electrolytic
(Optional)
Co2
10 µF
Ceramic
(Optional)
Inhibit
GND
North America (USA): 1-888-41-ASTEC
GND
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
ATH06T033 Series —3.3-V Input
6-A, 3.3-V Input Non-Isolated
Wide-Output Adjust Power Module
REVISION 00 (01DEC2003)
Ordering Information
Input Voltage
Output Voltage
2.95V to 3.65V
0.81 to 2.5V
Options:
“-J”
“-SJ”
“-S”
-
Output Current
Model Number
6A
ATH06T033-9(S)(J)
Through-hole Termination, Tray Packaging
SMT Termination, Tray Packaging
SMT Termination, T&R Packaging
Notes:
1
Preset output voltage is 0.8V; externally adjustable to 2.5V through the Vo,Adjust pin
Pin Descriptions
Vin: The positive input voltage power node to the module, which is referenced to common GND.
GND: This is the common ground connection for the
Vin and Vout power connections. It is also the 0 VDC
reference for the control inputs.
Vo Adjust: A 0.1 W 1 % resistor must be directly connected
between this pin and GND to set the output voltage to
a value higher than 0.8 V. The temperature stability of
the resistor should be 100 ppm/°C (or better). The setpoint range for the output voltage is from 0.8 V to 2.5 V.
The resistor value required for a given output voltage
may be calculated from the following formula. If this
pin is left open circuit, the output voltage will default to
its lowest value. For further information on output voltage adjustment consult the related application note.
Rset
= 10 kΩ ·
0.8 V
Vout – 0.8 V
Track: This is an analog control input that allows the
output voltage to follow another voltage during powerup and power-down sequences. The pin is active from
0 V up to the nominal set-point voltage. Within this
range the module’s 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
nominal output voltage. If unused, this input may be left
unconnected. For further information consult the related
application note.
– 2.49 kΩ
The specification table gives the preferred resistor values
for a number of standard output voltages.
North America (USA): 1-888-41-ASTEC
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
ADVANCE INFORMATION
Vout: The regulated positive power output with respect
to the GND node.
Inhibit: 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 pin is left
open-circuit, the module will produce an output whenever a valid input source is applied.
ATH06T033 Series —3.3-V Input
6-A, 3.3-V Input Non-Isolated
Wide-Output Adjust Power Module
Environmental & Absolute Maximum Ratings
Characteristics
Symbols
Track Input Voltage
Operating Temperature Range
Solder Reflow Temperature
Storage Temperature
Mechanical Shock
Vtrack
Ta
Treflow
Ts
Mechanical Vibration
Weight
Flammability
—
—
(Voltages are with respect to GND)
Conditions
Over Vin Range
Surface temperature of module body or pins
—
Per Mil-STD-883D, Method 2002.3
1 msec, ½ Sine, mounted
Mil-STD-883D, Method 2007.2
Suffix H
20-2000 Hz
Suffix S
Min
Typ
–0.3
–40 (i)
—
—
Max
Units
Vin + 0.3
85
235 (ii)
125
V
°C
°C
°C
–40
—
—
TBD
—
G’s
—
—
—
TBD
TBD
2.9
—
—
—
grams
G’s
Meets UL 94V-O
Notes: (i) For operation below 0 °C the external capacitors m ust bave stable characteristics. use either a low ESR tantalum, Os-Con®, or ceramic capacitor.
(ii) During reflow of SMD package version do not elevate peak temperature of the module, pins or internal components above the stated maximum.
ADVANCE INFORMATION
Specifications
(Unless otherwise stated, Ta =25 °C, V in =3.3 V, Vo =2.5 V, Co in =100 µF, Co1 =0 µF, Co2 =0 µF, and Io =Iomax)
Characteristics
Symbols
Conditions
Output Current
Input Voltage Range
Set-Point Voltage Tolerance
Temperature Variation
Line Regulation
Load Regulation
Total Output Variation
Io
Vin
Vo tol
∆Regtemp
∆Regline
∆Regload
∆Regtot
0.8 V ≤ Vo ≤ 2.5 V,
Over Io range
Efficiency
η
Vo Ripple (pk-pk)
Over-Current Threshold
Transient Response
Vr
Io trip
Track Input Current (pin 2)
Track Slew Rate Capability
Under-Voltage Lockout
ttr
∆Vtr
IIL track
dVtrack/dt
UVLO
Inhibit Control (pin4)
Input High Voltage
Input Low Voltage
Input Low Current
VIH
VIL
IIL inhibit
Input Standby Current
Switching Frequency
External Input Capacitance
External Output Capacitance
Reliability
Iin inh
ƒs
Cin
Cout
MTBF
Min
85 °C, natural convection
–40 °C <Ta < +85 °C
Over Vin range
Over Io range
Includes set-point, line, load,
–40 °C ≤ T a ≤ +85 °C
RSET = 2.21 kΩ Vo = 2.5 V
Io =4 A
RSET = 4.12 kΩ Vo = 2.0 V
RSET = 5.49 kΩ Vo = 1.8 V
RSET = 8.87 kΩ Vo = 1.5 V
RSET = 17.4 kΩ Vo = 1.2 V
RSET = 36.5 kΩ Vo = 1.0 V
20 MHz bandwidth, Co2 =10 µF ceramic
Reset, followed by auto-recovery
1 A/µs load step, 50 to 100 % Iomax,
Co1 =100 µF
Recovery Time
Vo over/undershoot
Pin to GND
Vtrack – Vo ≤ 50 mV and Vtrack < Vo(nom)
Vin increasing
Vin decreasing
Referenced to GND
0
2.95
—
—
—
—
ATH06T033
Typ
—
—
—
±0.5
±10
±12
Max
Units
6 (1)
3.65
±2 (2)
—
—
—
A
V
%Vo
%Vo
mV
mV
%Vo
—
—
±3
—
—
—
—
—
—
—
—
94
92
91
90
88
87
20 (3)
12
—
—
—
—
—
—
—
—
—
—
—
5
—
3.4
70
100
—
—
4.3
3.7
—
—
–130
—
4.45
—
Pin to GND
Inhibit (pin 4) to GND, Track (pin 2) open
Over Vin and Io ranges
Vin –0.5
–0.2
—
—
550
100 (5)
0
—
—
–130
10
600
—
100 (6)
Open
0.6
—
—
650
—
TBD
Per Bellcore TR-332
50 % stress, Ta =40 °C, ground benign
TBD
—
—
(2)
%
mVpp
A
(4)
µSec
mV
µA
V/ms
V
(4)
V
µA
mA
kHz
µF
µF
106 Hrs
Notes: (1) No derating is required when the module is soldered directly to a 4-layer PCB with 1 oz. copper.
(2) The set-point voltage tolerance is affected by the tolerance and stability ofRSET. The stated limit is unconditionally met if RSET has a tolerance of 1 %
with 100 ppm/°C or better temperature stability.
(3) The pk-pk output ripple voltage is measured with an external 10 µF ceramic capacitor. See the standard application schematic.
(4) This control pin has an internal pull-up to the input voltage Vin. If it is left open-circuit the module will operate when input power is applied. A small
low-leakage (<100 nA) MOSFET is recommended for control. For further information, consult the related application note.
(5) A 100 µF input capacitor is required for proper operation. The capacitor must be rated for a minimum of 300 mA rms of ripple current.
(6) An external output capacitor is not required for basic operation. Adding 100 µF of distributed capacitance at the load will improve the transient response.
North America (USA): 1-888-41-ASTEC
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
ATH06T033 Series —3.3-V Input
Typical Characteristics
6-A, 3.3-V Input Non-Isolated
Wide-Output Adjust Power Module
Characteristic Data; Vin =3.3 V
(See Note A)
Efficiency vs Load Current
100
Efficiency - %
90
VOUT
2.5 V
1.8 V
1.5 V
1.2 V
1.0 V
80
70
60
50
0
1
2
3
4
5
6
Iout - Amps
Output Ripple vs Load Current (See Note 3 to Table)
50
VOUT
ADVANCE INFORMATION
Ripple - mV
40
1.8 V
1.5 V
1.2 V
1.0 V
2.5 V
30
20
10
0
0
1
2
3
4
5
6
Iout - Amps
Power Dissipation vs Load Current
1.2
1
Pd - Watts
0.8
0.6
0.4
0.2
0
0
1
2
3
4
5
6
Iout - Amps
The products listed hereunder are prototype or pre-production devices which have not been fully qualified to Astec’s
specifications. Product specifications are subject to change without notice. Astec makes no warranty, either expressed,
implied, or statutory, including implied warranty of merchantability or fitness for a specific purpose, of these products.
Note A: Characteristic data has been developed from actual products tested at 25°C. This data is considered typical data for the Converter.
North America (USA): 1-888-41-ASTEC
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
Application Notes
ATH06T033 & ATH06T05 Series
Adjusting the Output Voltage of the ATH06T033
& ATH06T05 Wide-Output Adjust Power Modules
The Vo Adjust control (pin 5) sets the output voltage to a
value higher than 0.8 V. The adjustment range of the
ATH06T033 (3.3-V input) is from 0.8 V to 2.5 V 1, and
the ATH06T05-9xx (5-V input) from 0.8 V to 3.6 V. The
adjustment method requires the addition of a single
external resistor, Rset, that must be connected directly
between the Vo Adjust and GND pins 2. Table 1-1 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.
For other output voltages the value of the required resistor
can either be calculated using the following formula, or
simply selected from the range of values given in Table 1-2.
Figure 1-1 shows the placement of the required resistor.
Rset
0.8 V
Vout – 0.8 V
= 10 kΩ ·
– 2.49 kΩ
Table 1-1; Preferred Values of Rset for Standard Output Voltages
Vout (Standard)
Rset (Pref’d Value)
3.3 V 1
2.5 V
2V
1.8 V
1.5 V
1.2 V
1V
0.8 V
698 Ω
2.21 kΩ
4.12 kΩ
5.49 kΩ
8.87 kΩ
17.4 kΩ
36.5 kΩ
Open
Vout (Actual)
3.309V
2.502 V
2.010 V
1.803 V
1.504 V
1.202 V
1.005 V
0.8 V
Figure 1-1; Vo Adjust Resistor Placement
2
Table 1-2; Output Voltage Set-Point Resistor Values
Va Req’d
0.800
0.825
0.850
0.875
0.900
0.925
0.950
0.975
1.000
1.025
1.050
1.075
1.100
1.125
1.150
1.175
1.200
1.225
1.250
1.275
1.300
1.325
1.350
1.375
1.400
1.425
1.450
1.475
1.50
1.55
1.60
1.65
1.70
1.75
1.80
1.85
1.90
1.95
Rset
Open
318 kΩ
158 kΩ
104 kΩ
77.5 kΩ
61.5 kΩ
50.8 kΩ
43.2 kΩ
37.5 kΩ
33.1 kΩ
29.5 kΩ
26.6 kΩ
24.2 kΩ
22.1 kΩ
20.4 kΩ
18.8 kΩ
17.5 kΩ
16.3 kΩ
15.3 kΩ
14.4 kΩ
13.5 kΩ
12.7 kΩ
12.1 kΩ
11.4 kΩ
10.8 kΩ
10.3 kΩ
9.82 kΩ
9.36 kΩ
8.94 kΩ
8.18 kΩ
7.51 kΩ
6.92 kΩ
6.4 kΩ
5.93 kΩ
5.51 kΩ
5.13 kΩ
4.78 kΩ
4.47 kΩ
Va Req’d
2.00
2.05
2.10
2.15
2.20
2.25
2.30
2.35
2.40
2.45
2.50
2.55
2.60
2.65
2.70
2.75
2.80
2.85
2.90
2.95
3.00
3.05
3.10
3.15
3.20
3.25
3.30
3.35
3.40
3.45
3.50
3.55
3.60
Rset
4.18 kΩ
3.91 kΩ
3.66 kΩ
3.44 kΩ
3.22 kΩ
3.03 kΩ
2.84 kΩ
2.67 kΩ
2.51 kΩ
2.36 kΩ
2.22 kΩ
2.08 kΩ
1.95 kΩ
1.83 kΩ
1.72 kΩ
1.61 kΩ
1.51 kΩ
1.41 kΩ
1.32 kΩ
1.23 kΩ
1.15 kΩ
1.07 kΩ
988 Ω
914 Ω
843 Ω
775 Ω
710 Ω
647 Ω
587 Ω
529 Ω
473 Ω
419 Ω
367 Ω
Track
3
VIN
ATH06T05-9J
PTH05050W
Inhibit
3
VO
GND
1
4
RSET
1%
0.1 W
CIN
100 µF
(Required)
VOUT
6
GND
North America (USA): 1-888-41-ASTEC
+
VIN
COUT
100 µF
(Optional)
Notes:
1. Modules that operate from a 3.3-V input bus should
not be adjusted higher than 2.5 V.
2. Use a 0.1 W resistor. 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 5 and 1 using dedicated
PCB traces.
3. Never connect capacitors from Vo Adjust to either GND or
Vout. Any capacitance added to the Vo Adjust pin will affect
the stability of the regulator.
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
+
Application Notes
ATH06T033 & ATH06T05 Series
ATH06T033/T05: Capacitor Recommendations
Input Capacitor
The recommended input capacitance is determined by
100 µF minimum capacitance, and 300 mA (rms) minimum ripple current rating.
Ripple current and less than 300 mΩ equivalent series
resistance (ESR) values are the major considerations,
along with temperature, when designing with different
types of capacitors.
Tantalum capacitors have a recommended minimum voltage rating of twice 2× (the maximum DC voltage + AC
ripple). This is standard practice for tantalum capacitors
to insure reliability.
Output Capacitors (Optional)
The ESR of the recommended capacitors is equal to or
less than 300 mΩ. Electrolytic capacitors have marginal
ripple performance at frequencies greater than 400 kHz
but excellent low frequency transient response. Above the
ripple frequency, ceramic capacitors are necessary to
improve the transient response and reduce any high
frequency noise components apparent during higher
current excursions.
Tantalum capacitors are acceptable on the output bus.
Tantalum, Os-con, or ceramic capacitor types are recommended for applications where ambient temperatures fall
below 0 °C. Ceramic capacitors may be used instead of
electrolytic types on both the input and output bus. The
input bus must have the minimum amount of capacitance.
A single 10 µF ceramic capacitor may also be used on the
output bus to reduce output ripple.
Capacitor Table
Table 2-1 identifies the characteristics of capacitors from
a number of vendors with acceptable ESR and ripple
current (rms) ratings. The number of capacitors required
at both the input and output buses is identified for
each capacitor type.
This is not an extensive capacitor list. Capacitors from other
vendors are available with comparable specifications. Those
listed are for guidance. The RMS ripple current rating and
ESR are the critical parameters necessary to insure both optimum regulator performance and long capacitor life.
Tantalum/ Ceramic Capacitors
Table 2-1: Recommended Input/Output Capacitors
Capacitor Vendor/
Component
Series
Capacitor Characteristics
Quantity
Working
Voltage
Value (µF)
(ESR) Equivalent
Series Resistance
Max Ripple
at 85 °C
Current (Irms)
Physical Size
(mm)
Input
Bus
Output
Bus
Panasonic FC (SMT
WA (SMT)
25 V
10 V
100 µF
120 µF
0.300 Ω
0.035 Ω
450 mA
2800 mA
8×10
8.3×6.9
1
1
1
1
EEVFC1E101P
EEFWA1A121P
Panasonic FC
FK (SMT)
16 V
16 V
220 µF
330 µF
0.150 Ω
0.160 Ω
555 mA
600 mA
10×10.2
8×10.2
1
1
1
1
EEUFC1C221
EEVFK1C331P
United Chemi–Con
FS
PXA (SMT)
MVZ (SMT)
PS
10 V
10 V
16 V
10 V
100 µF
120 µF
220 µF
270 µF
0.040 Ω
0.027 Ω
0.170 Ω
0.014 Ω
2100 mA
2430 mA
450 mA
4420 mA
6.3×9.8
8×6.7
8×10
8×11.5
1
1
1
1
1
1
1
1
10FS100M
PXA10VC121MH80TP
MVZ25VC221MH10TP
10PS270MH11
Nichicon
WG (SMT)
F55
PM
35 V
10 V
25 V
100 µF
100 µF
150 µF
0.150 Ω
0.055 Ω
0.160 Ω
670 mA
2000 mA
460 mA
10×10
7,7x4,3
10×11.5
1
1
1
1
1
1
UWG1V101MNR1GS
F551A107MN
UPM1E151MPH
Sanyo Os-con®
SVP (SMT)
SP
TPA
10 V
16 V
10 V
120 µF
100 µF
100 µF
0.040 Ω
0.025 Ω
0.080 Ω
>2500 mA
>2800 mA
>1200 mA
7×8
6.3×9.8
7.3×4.8
1
1
1
1
1
1
10SVP120M
16SPS100M
10TPA100M
AVX Tantalum TPS
10 V
10 V
100 µF
220 µF
0.100 Ω
0.100 Ω
>1090 mA
>1414 mA
7.3L
×4.3W ×4.1H
1
1
1
1
TPSD107M010R0100
TPSV227M010R0100
Kemet T520
T495
10 V
10 V
100 µF
100 µF
0.080 Ω
0.100 Ω
1200 mA
>1100 mA
7.3L ×5.7W
×4.0H
1
1
1
1
T520D107M010AS
T495X107M010AS
Sprague 594D/595D
10 V
10 V
150 µF
120 µF
0.090 Ω
0.140 Ω
1100 mA
>1000 mA
7.3L
×6.0W ×4.1H
1
1
1
1
594D157X0010C2T
595D127X0010D2T
TDK- Ceramic X5R
Murata Ceramic X5R
1210 Case
6.3 V
6.3 V
47 µF
47 µF
0.002 Ω
0.002 Ω
>1400 mA
>1000 mA
3.6L
×2.8W ×2.8H
2
2
2
2
C3225X5R0J476KT/MT
GRM32ER60J476M/6.3
North America (USA): 1-888-41-ASTEC
Europe (UK): 44(1384)842-211
Vendor Number
Asia (HK): 852-2437-9662
Application Notes
ATH Series of Wide-Output Adjust Power
Modules (3.3/5-V Input)
Features of the ATH Family of Non-Isolated
Wide Output Adjust Power Modules
This is a feature unique to the ATH family, and was
specifically designed to simplify the task of sequencing the
supply voltage in a power system. These and other features
are described in the following sections.
Point-of-Load Alliance
The ATH family of non-isolated, wide-output adjust
power modules are optimized for applications that require
a flexible, high performance module that is small in size.
These products are part of the “Point-of-Load Alliance”
(POLA), which ensures compatible footprint,
interoperability and true second sourcing for customer
design flexibility. The POLA is a collaboration between
Texas Instruments, Artesyn Technologies, and Astec
Power to offer customers advanced non-isolated modules
that provide the same functionality and form factor. Product series covered by the alliance includes the ATH06
(6 A), ATH10 (10 A), ATH12/15 (12/15 A), ATH18/22
(18/22 A), and the ATH26/30 (26/30 A).
From the basic, “Just Plug it In” functionality of the 6-A
modules, to the 30-A rated feature-rich ATH30 Series,
these products were designed to be very flexible, yet simple
to use. The features vary with each product. Table 3-1
provides a quick reference to the available features by
product and input bus voltage.
6A
3.3 V / 5 V
10 A
12 V
10
8 AA
3.3 V / 5 V
15 A
12 V
12 A
3.3 V / 5 V
22 A
12 V
18 A
3.3 V / 5 V
30 A
12 V
26 A
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Thermal Shutdown
•
•
•
•
•
•
•
•
•
•
•
Pre-Bias Startup
•
•
•
•
•
•
•
•
•
•
•
Output Sense
12 V
•
•
•
•
•
•
•
•
•
•
•
Margin Up/Down
PTHxx030
ATH26/30
6A
Auto-Track™
PTHxx020
ATH18/22
6A
5V
Over-Current
PTHxx010
ATH12/15
3.3 V
On/Off Inhibit
ATH10
PTHxx060
I OUT
Adjust (Trim)
PTHxx050
ATH06
Input Bus
Vo (2V/Div)
Iin (2A/Div)
Vin (5V/Div)
HORIZ SCALE: 10ms/Div
•
•
•
•
For simple point-of-use applications, the ATH06 (6A)
provides operating features such as an on/off inhibit,
output voltage trim, pre-bias startup (3.3/5-V input only),
and over-current protection. The ATH10 (10 A), and
ATH12/15 (12/15 A) include an output voltage sense, and
margin up/down controls. Then the higher output current,
ATH18/22 (18/22A) and ATH26/30 (26/30A) products incorporate over-temperature shutdown protection. All of the
products referenced in Table 3-1 include Auto-Track™.
North America (USA): 1-888-41-ASTEC
When configured per their standard application all the
ATH products will produce a regulated output voltage following the application of a valid input source voltage. All
the modules include soft-start circuitry. This slows the initial
rate in which the output voltage can rise, thereby limiting
the amount of in-rush current that can be drawn from the
input source. The soft-start circuitry also introduces a short
time delay (typically 5 ms-10 ms) into the power-up
characteristic. This delay is from the point that a valid
input source is recognized, to the initial rise of the output
voltage. Figure 3-1 shows the power-up characteristic of
the 22-A output product (ATH22T05-9xx), operating from a
5-V input bus and configured for a 3.3-V output. The waveforms were measured with a 5-A resistive load. The initial
rise in input current when the input voltage first starts to
rise is the charge current drawn by the input capacitors.
Figure 3-1
Table 3-1; Operating Features by Series and Input Bus Voltage
Series
Power-Up Characteristics
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.
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
Application Notes
ATH Series of Wide-Output Adjust Power
Modules (3.3/5-V Input)
Output On/Off Inhibit
Remote Sense
For applications requiring output voltage on/off control,
each series of the ATH 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 ATH10, ATH12/15, ATH18/22, and ATH26/30
products incorporate an output voltage sense pin,
Vo Sense. The Vo Sense pin should be connected to Vout at the
load circuit (see data sheet standard application). A remote sense improves the load regulation performance of
the module by allowing it to compensate for any ‘IR’ voltage
drop between itself and the load. An IR drop is caused by
the high output current flowing through the small
amount of pin and trace resistance. Use of the remote
sense is optional. If not used, the Vo Sense pin can be left
open-circuit. An internal low-value resistor (15-Ω or
less) is connected between the Vo Sense and Vout. This ensures the output voltage remains in regulation.
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 Vin with
respect to GND.
Figure 3-2 shows the typical application of the inhibit
function. Note the discrete transistor (Q1). The Inhibit
control has its own internal pull-up to Vin potential. The
input is not compatible with TTL logic devices. An opencollector (or open-drain) discrete transistor is recommended
for control.
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
20 msec. Figure 3-3 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 load.
Figure 3-2
Vo Sense
VIN
2
8
1
7
+
Q1
BSS138
VOUT
6
4
RSET
COUT
330 µF
L
O
A
D
1 =Inhibit
GND
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.
Over-Temperature Protection
5
ATH15T05-9S
PTH05020W
3
CIN
1,000 µF
9
+
10
With the sense pin connected, the difference between
the voltage measured directly between the Vout and GND
pins, and that measured from V o 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.
GND
Figure 3-3
Vo (2V/Div)
Iin (2A/Div)
The ATH18/22 and ATH26/30 series of products have
over-temperature 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 automatically 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.
Q1Vds (5V/Div)
HORIZ SCALE: 10ms/Div
North America (USA): 1-888-41-ASTEC
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
Application Notes
ATH Series of Wide-Output Adjust Power
Modules (3.3/5-V Input)
Auto-Track™ Function
The Auto-Track™ function is unique to the ATH family,
and is available with the all “Point-of-Load Alliance”
(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 DSPs, micro-processors, and ASICs.
How Auto-Track™ Works
Auto-Track™ works by forcing the module’s output voltage
to follow a voltage presented at the Track control pin. This
control range is limited to between 0 V and the module’s
set-point voltage. Once the track-pin voltage is raised
above the set-point voltage, the module’s output remains
at its set-point 1. As an example, if the Track pin of a 2.5-V
regulator is at 1 V, the regulated output will be 1 V. But
if the voltage at the Track pin rises to 3 V, the regulated
output will not go higher than 2.5 V.
When under track control, the regulated output from
the module follows the voltage at its Track pin on a voltfor-volt basis. By connecting the Track pin of a number
of these modules together, the output voltages will 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. The Track control also incorporates an
internal RC charge circuit. This operates off the module’s
input voltage to produce a suitable rising waveform at
power up.
Typical Application
The basic implementation of Auto-Track™ allows for
simultaneous voltage sequencing of a number of AutoTrack™ compliant modules. Connecting the Track control
pins of two or more modules forces the Track control of
all modules to follow the same collective RC ramp waveform, and allows them to be controlled through a single
transistor or switch; Q1 in Figure 3-4.
each module will rise in unison with other modules, to its
respective set-point voltage.
Figure 3-5 shows the output voltage waveforms from the
circuit of Figure 3-4 after the On/Off Control is set from a
high to a low-level voltage. The waveforms, Vo1 and Vo2
represent the output voltages from the two power modules, U1 (3.3 V) and U2 (2.0 V) respectively. Vo1 and Vo2
are shown rising together to produce the desired simultaneous power-up characteristic.
The same circuit also provides a power-down sequence.
Power down is the reverse of power up, and is accomplished by lowering the track control voltage back to zero
volts. The important constraint is that a valid input voltage
must be maintained until the power down is complete. It
also requires that Q1 be turned off relatively slowly. This
is so that the Track control voltage does not fall faster than
Auto-Track's slew rate capability, which is 5 V/ms. The
components R1 and C1 in Figure 3-4 limit the rate at
which Q1 can pull down the Track control voltage. The
values of 100 k-ohm and 0.047 µF correlate to a decay
rate of about 0.6 V/ms.
The power-down sequence is initiated with a low-to-high
transition at the On/Off Control input to the circuit.
Figure 3-6 shows the power-down waveforms. As the
Track control voltage falls below the nominal set-point
voltage of each power module, then its output voltage
decays with all the other modules under Auto-Track™
control.
Notes on Use of Auto-Track™
1. The Track pin voltage must be allowed to rise above
the module’s set-point voltage before the module can
regulate at its adjusted set-point voltage.
2. The Auto-Track™ function will track almost any
voltage ramp during power up, and is compatible
with ramp speeds of up to 5 V/ms.
3. The absolute maximum voltage that may be applied to the
Track pin is Vin.
To initiate a power-up sequence, it is recommended that
the Track control be first pulled to ground potential.
This should be done at or before input power is applied
to the modules, and then held for at least 10 ms thereafter. This brief period gives the modules time to complete
their internal soft-start initialization. Applying a logiclevel high signal to the circuit’s On/Off Control turns
Q1 on and applies a ground signal to the Track pins. After
completing their internal soft-start intialization, the output of all modules will remain at zero volts while Q1 is on.
4. The module will not follow a voltage at its Track control
input until it has completed its soft-start initialization.
This takes about 10 ms from the time that the module
has sensed that a valid voltage has been applied its input.
During this period, it is recommended that the Track
pin be held at ground potential.
10 ms after a valid input voltage has been applied to the
modules, Q1 may be turned off. This allows the track control voltage to automatically rise toward to the modules'
input voltage. During this period the output voltage of
6. The Auto-Track™ function can be disabled by
connecting the Track pin to the input voltage (Vin)
through a 1-kΩ resistor. When Auto-Track™ is
disabled, the output voltage will rise faster
following the application of input power.
5. Once its soft-start initialization is complete, the module
is capable of both sinking and sourcing current when
following the voltage at the Track pin.
**Auto-Track is a trademark of Texas Instruments, Inc.
North America (USA): 1-888-41-ASTEC
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
Application Notes
ATH Series of Wide-Output Adjust Power
Modules (3.3/5-V Input)
Figure 3-4; Sequenced Power Up & Power Down Using Auto-Track
U1
10
9
8
5
Track
Inhibit
+
CIN
ATH22T05-9SJ
PTH05020W
VIN
VO
Vo1 =3.3V
6
GND
3
7
1
COUT
4
R2
698
+
2
+5V
C1
0.047µF
U2
9
8
5
Track
2
CIN
0V
Figure 3-5; Simultaneous Power Up with Auto-Track Control
+
R1
100k
10
Q1
BSS138
ATH15T05-9SJ
PTH05010W
VIN
Inhibit
3
VO
Vo2 =2V
6
GND
1
7
4
R3
4k12
COUT
+
On/Off Control
1 = Power Down
0 = Power Up
Figure 3-6; Simultaneous Power Down with Auto-Track Control
Vo1 (1V/Div)
Vo1 (1V/Div)
Vo2 (1V/Div)
Vo2 (1V/Div)
On/Off Input
(5V/Div)
On/Off Control
(5V/Div)
HORIZ SCALE: 5ms/Div
HORIZ SCALE: 5ms/Div
North America (USA): 1-888-41-ASTEC
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
Application Notes
ATH Series of Wide-Output Adjust Power
Modules (3.3/5-V Input)
Margin Up/Down Controls
Notes:
The ATH10 (10A), ATH12/15 (12/15A), ATH18/22 (18/
22A) and ATH26/30 (26/30A) products incorporate Margin
Up and Margin Down control inputs. These controls allow
the output voltage to be momentarily adjusted 1, 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 Vo Adjust pin.
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.
The 5 % adjustment is made by pulling the appropriate
margin control input directly to the GND terminal 2.
A low-leakage open-drain device, such as an n-channel
MOSFET or p-channel JFET is recommended for this
purpose 3. Adjustments of less than 5 % can also be accommodated by adding series resistors to the control inputs
(See Figure 3-4). The value of the resistor can be selected
from Table 3-2, or calculated using the following formula.
2. The ground reference should be a direct connection to
the module GND at pin 7 (pin 1 for the ATH06).
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 something less than
5 %, series resistors are required (See RD and RU in
Figure 3-7). For the same amount of adjustment, the
resistor value calculated for RU and RD will be the same.
The formulas is as follows.
RU or RD =
499
∆%
– 99.8
Table 3-2; Margin Up/Down Resistor Values
% Adjust
5
4
3
2
1
kΩ
Where ∆% = The desired amount of margin adjust in
percent.
RU / RD
0.0 kΩ
24.9 kΩ
66.5 kΩ
150.0 kΩ
397.0 kΩ
Figure 3-7; Margin Up/Down Application Schematic
10
9
8
1
7
PTH05010W
ATH15T05-9S
+Vo
0V
(Top View)
VIN
2
3
+
RD
4
MargUp
5
RU
RSET
0.1 W, 1 %
Cin
MargDn
+VOUT
6
+
Cout
Q2
GND
North America (USA): 1-888-41-ASTEC
L
O
A
D
Q1
GND
Europe (UK): 44(1384)842-211
Asia (HK): 852-2437-9662
Application Notes
ATH Series of Wide-Output Adjust Power
Modules (3.3/5-V Input)
Pre-Bias Startup Capability
Notes
Only selected products in the ATH family incorporate this
capability. Consult Table 3-1 to identify which products
are compliant.
1. Startup is the relatively short period (approx. 10 ms)
prior to the output voltage rising. The startup period
immediately follows either the application of a valid
input source voltage, or the release of a ground signal
at the Inhibit pin.
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 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, these types of
modules can sink as well as source output current.
2. To ensure that the regulator 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 output voltage throughout the
power-up and power-down sequence.
3. The Auto-Track function can be disabled at power up
by immediately applying a voltage to the module’s Track
pin that is greater than its set-point voltage. This can
be easily accomplished by connecting the Track pin to
Vin through a 1-kΩ resistor.
The ATH family of power modules incorporate synchronous rectifiers, but will not sink current during startup 1,
or whenever the Inhibit pin is held low. However, to ensure
satisfactory operation of this function, certain conditions
must be maintained. 2 Figure 3-7 shows an application
demonstrating the pre-bias startup capability. The startup waveforms are shown in Figure 3-9. Note that the
output current from the ATH15T033-9xx (Io) shows negligible current until its output voltage rises above that
backfed through diodes D1 and D2.
Figure 3.9; Pre-Bias Startup Waveforms
Vin (1 V/Div)
Vo (1 V/Div)
Note: The pre-bias start-up feature is not compatible with
Auto-Track. When the module is under Auto-Track control, it
is fully active and will sink current if the output voltage is
below that of a back-feeding source. Therefore to ensure a prebias hold-off, one of two approaches must be followed when
input power is applied to the module. The Auto-Track function
must either be disabled 3, or the module’s output held off using
the Inhibit pin. The latter allows Auto-Track’s internal (RC)
voltage ramp to rise above the set-point voltage.
Io (5 A/Div)
HORIZ SCALE: 5 ms/Div
Figure 3.8; Application Circuit Demonstrating Pre-Bias Startup
VIN = 3.3 V
R1
1k0
10
9
5
8
Track
2
VIN
Sense
ATH15T033-9S
PTH03010W
Inhibit
3
GND
1
VO
Vo = 2.5 V
6
+
Vadj
7
D1, D2
MBR3100
Io
4
VCCIO
VCORE
+
CIN
330 µF
North America (USA): 1-888-41-ASTEC
R2
2k21
+
COUT
330 µF
Europe (UK): 44(1384)842-211
ASIC
Asia (HK): 852-2437-9662
Through Hole Termination
Surface Mount Termination
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