ETC PTH05000W

PTH05000 Series —5-V Input
6-A, 5-V Input Non-Isolated
Wide-Output Adjust Power Module
SLTS201B – MAY 2003 – REVISED AUGUST 2003
Features
NOMINAL SIZE =
0.75 in x 0.5 in
(19,05 mm x 12,7 mm)
• Up to 6-A Output Current
• 5-V Input Voltage
• Wide-Output Voltage Adjust
(0.9 V to 3.6 V)
• Efficiencies up to 94 %
• 160 W/in³ Power Density
• On/Off Inhibit
• Under-Voltage Lockout
• Output Current Limit
•
•
•
•
•
•
Pre-Bias Startup
Over-Temperature Protection
Surface Mountable
Operating Temp: –40 to +85 °C
DSP Compatible Output Voltages
IPC Lead Free 2
Description
Pin Configuration
The PTH05000 series of non-isolated
power modules are small in size and high
on performance. Using double-sided surface mount construction and synchronous
rectification technology, these regulators
deliver up to 6 A of output current while
occupying a PCB area of about half the
size of a standard postage stamp. They
are an ideal choice for applications where
space, performance and cost are important design constraints.
The series operates from an input
voltage of 5 V to provide step-down
power conversion to any output voltage
over the range, 0.9 V to 3.6 V. The output voltage of the PTH05000W is set
within this range using a single resistor.
Operating features include an on/off
inhibit, output voltage adjust (trim), an
output current limit, and over-temperature protection.
For high efficiency these parts employ
a synchronous rectifier output stage. An
output pre-bias holdoff 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, or ASIC.
Package options include both throughhole and surface mount configurations.
Pin
1
2
3
4
5
Function
GND
Vin
Inhibit *
Vo Adjust
Vout
* Denotes negative logic:
Open
= Output On
Ground = Output Off
Standard Application
1
2
Inhibit
PTH05000W
(Top View)
3
4
+
CIN
330 µF
(Required)
VOUT
5
GND
RSET
1 %, 0.1 W
(Required)
COUT
100 µF
(Optional)
+
VIN
GND
Rset = Reistor to set the desired output
voltage (see spec. table for values)
Cin = Required electrolytic 330 µF
Cout = Recommended 100 µF electrolytic
For technical support and more information, see inside back cover or visit www.ti.com
PTH05000 Series —5-V Input
6-A, 5-V Input Non-Isolated
Wide-Output Adjust Power Module
SLTS201B – MAY 2003 – REVISED AUGUST 2003
Ordering Information
Output Voltage (PTH05000Hxx)
Package Options (PTH05000xHH) (1)
Code
W
Code
Voltage
0.9 V – 3.6 V (Adjust)
AH
AS
Description
Pkg Ref.
Horiz. T/H
SMD, Standard (3)
(2)
(EUS)
(EUT)
Notes: (1) Add “T” to end of part number for tape and reel on SMD packages only.
(2) Reference the applicable package reference drawing for the dimensions and PC board layout
(3) “Standard” option specifies 63/37, Sn/Pb pin solder material.
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 ‘Inhibit’ and ‘Vo Adjust’ control input.
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 opencircuit, the module will produce an output whenever a
valid input source is applied.
Vo Adjust: A 0.1 W, 1 % 100 ppm/°C resistor must be
connected between this pin and the GND pin to set the
output voltage to the desired value. The set point range
for the output voltage is from 0.9 V to 3.6 V. The resistor
required for a given output voltage may be calculated
from the following formula. If left open circuit, the
module output will default to its lowest output voltage
value. For further information on the adjustment and/or
trimming of the output voltage, consult the related application note.
Rset
= 10 kΩ ·
0.891 V
Vout – 0.9 V
– 3.24 kΩ
The specification table gives the preferred resistor values
for a number of standard output voltages.
For technical support and more information, see inside back cover or visit www.ti.com
PTH05000 Series —5-V Input
6-A, 5-V Input Non-Isolated
Wide-Output Adjust Power Module
SLTS201B – MAY 2003 – REVISED AUGUST 2003
Environmental & Absolute Maximum Ratings
(Voltages are with respect to GND)
Characteristics
Symbols
Conditions
Min
Typ
Max
Units
Operating Temperature Range
Solder Reflow Temperature
Storage Temperature
Over Temperature Protection
Mechanical Shock
Ta
Treflow
Ts
OTP
Over Vin Range
Surface temperature of module body or pins
—
IC junction temperature
Per Mil-STD-883D, Method 2002.3
1 msec, ½ sine, mounted
Mil-STD-883D, Method 2007.2
20-2000 Hz
–40 (i)
—
–40
—
—
150
+85
215 (ii)
+125
—
°C
°C
°C
°C
—
500
—
G’s
—
20
—
G’s
—
2
—
grams
Mechanical Vibration
Weight
Flammability
—
—
Meets UL 94V-O
Notes: (i) For operation below 0 °C the external capacitors must have stable characteristics. Use either a low ESR tantalum, Oscon®, 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. For
further guidance refer to the application note, “Reflow Soldering Requirements for Plug-in Power Surface Mount Products.”
Electrical Specifications
Unless otherwise stated, T a =25 °C, Vin =5 V, V o =3.3 V, C in =330 µF, C out =0 µF, and Io =Io (max)
Characteristics
Symbols
Conditions
Output Current
Io
0.9 V ≤ Vo ≤3.6 V,
Input Voltage Range
Set-Point Voltage Tolerance
Temperature Variation
Line Regulation
Load Regulation
Total Output Variation
Vin
Vo tol
∆Regtemp
∆Regline
∆Regload
∆Regtot
Over Io range
Efficiency
η
Vo = 3.3 V
Vo = 2.5 V
Vo = 2.0 V
Vo = 1.8 V
Vo = 1.5 V
Vo = 1.2 V
Vo = 1.0 V
Vo ≥3.3 V
Vo ≤2.5 V
1 A/µs load step, 50 to 100 % Iomax,
Vo =1.8 V, Cout =100 µF
Recovery time
Vo over/undershoot
∆Vo = –50 mV
Vin increasing
Vin decreasing
Referenced to GND
Vo Ripple (pk-pk)
Vr
Transient Response
Current Limit
Under-Voltage Lockout
ttr
∆Vtr
Ilim
UVLO
Inhibit Control (pin 3)
Input High Voltage
Input Low Voltage
Input Low Current
VIH
VIL
IIL
Standby Input Current
Switching Frequency
External Input Capacitance
External Output Capacitance
Reliability
Iin standby
ƒs
Cin
Cout
MTBF
Min
PTH05000W
Typ
Max
Units
0
0
4.5
—
—
—
—
—
—
—
—
±0.5
±5
±5
6 (1)
5.25 (1)
5.5
±2 (2)
—
—
—
A
V
%Vo
%Vo
mV
mV
—
—
±3 (2)
%Vo
—
—
—
—
—
—
—
—
—
92
90
88
87
84
82
79
30
25
—
—
—
—
—
—
—
—
—
—
—
—
—
3.4
70
100
13
3.8
3.5
—
—
—
4.3
—
Pin 3 to GND
pins 1 & 3 connected
Over Vin and Io ranges
Vin –0.5
–0.2
—
—
—
330 (4)
0
—
—
–10
1
700
—
100
Open (3)
0.8
—
—
—
—
1,000
Per Bellcore TR-332
50 % stress, Ta =40 °C, ground benign
28
—
Ta =25 °C, natural convection
Ta =60 °C, 200LFM
–40 °C <Ta < +85 °C
Over Vin range
Over Io range
Includes set-point, line, load,
–40 °C ≤ T a ≤ +85 °C
RSET = 475 Ω
Vin =5 V, Io =4 A
RSET = 2.32 kΩ
RSET = 4.87 kΩ
RSET = 6.65 kΩ
RSET = 11.5 kΩ
RSET = 26.1 kΩ
RSET = 84.5 kΩ
20 MHz bandwidth
(5)
—
%
mVpp
µSec
mV
A
V
V
µA
mA
kHz
µF
µF
106 Hrs
Notes: (1) See SOA curves or consult factory for appropriate derating.
(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 Inhibit control (pin 3) has an internal pull-up to Vin, and if left open-circuit the module will operate when input power is applied. A small lowleakage (<100 nA) MOSFET is recommended to control this input. See application notes for more information.
(4) The regulator requires a minimum of 330 µF input capacitor with a minimum 300 mArms ripple current rating. For further information, consult the
related application note on Capacitor Recommendations.
(5) An external output capacitor is not required for basic operation. Adding 100 µF of distributed capacitance at the load will improve the transient response.
For technical support and more information, see inside back cover or visit www.ti.com
PTH05000 Series —5-V Input
Typical Characteristics
6-A, 5-V Input Non-Isolated
Wide-Output Adjust Power Module
Characteristic Data; Vin =5 V
SLTS201B – MAY 2003 – REVISED AUGUST 2003
Safe Operating Area; Vin =5 V
(See Note A)
Efficiency vs Output Current
Output Voltage =3.3 V
100
90
3.3 V
2.5 V
2.0 V
1.8 V
1.5 V
1.2 V
1.0 V
80
70
60
Ambient Temperature (°C)
80
VOUT
90
Efficiency - %
(See Note B)
Airflow
70
400LFM
200LFM
100LFM
Nat Conv
60
50
40
30
50
20
0
1
2
3
4
5
6
0
Iout - Amps
1
2
3
4
5
6
Iout (A)
Ripple vs Output Current
50
VOUT
Ripple - mV
40
3.3 V
2.5 V
2.0 V
1.8 V
1.5 V
1.2 V
1.0 V
30
20
10
0
0
1
2
3
4
5
6
Iout - Amps
Power Dissipation vs Output Current
3
2.5
Pd - Watts
2
1.5
1
0.5
0
0
1
2
3
4
5
6
Iout - Amps
Note A: Characteristic data has been developed from actual products tested at 25 °C. This data is considered typical data for the Converter.
Note B: SOA curves represent the conditions at which internal components are at or below the manufacturer’s maximum operating temperatures. Derating limits apply to
modules soldered directly to a 4 in. × 4 in. double-sided PCB with 1 oz. copper.
For technical support and more information, see inside back cover or visit www.ti.com
Application Notes
PTH05000W
Adjusting the Output Voltage of the PTH05000W
Wide-Output Adjust Power Modules
The Vo Adjust control (pin 4) sets the output voltage of
the PTH05000Wproduct. The adjustment range is
from 0.9 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 1. 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
= 10 kΩ ·
0.891 V
Vout – 0.9 V
– 3.24 kΩ
Table 1-1; Preferred Values of Rset for Standard Output Voltages
Vout (Standard)
Rset (Pref’d Value)
3.3 V
2.5 V
2V
1.8 V
1.5 V
1.2 V
1V
0.9 V
475 Ω
2.32 kΩ
4.87 kΩ
6.65 kΩ
11.5 kΩ
26.1 kΩ
84.5 kΩ
Open
Vout (Actual)
3.298V
2.502 V
1.999 V
1.801 V
1.504 V
1.204 V
1.001 V
0.9 V
Figure 1-1; Vo Adjust Resistor Placement
Table 1-2; Output Voltage Set-Point Resistor Values
Va Req’d
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
353 kΩ
175 kΩ
116 kΩ
85.9 kΩ
68.0 kΩ
56.2 kΩ
47.7 kΩ
41.3 kΩ
36.4 kΩ
32.4 kΩ
29.2 kΩ
26.5 kΩ
24.2 kΩ
22.2 kΩ
20.5 kΩ
19.0 kΩ
17.7 kΩ
16.6 kΩ
15.5 kΩ
14.6 kΩ
13.7 kΩ
13.0 kΩ
12.3 kΩ
11.6 kΩ
10.5 kΩ
9.49 kΩ
8.64 kΩ
7.90 kΩ
7.24 kΩ
6.66 kΩ
6.14 kΩ
5.67 kΩ
5.25 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
4.86 kΩ
4.51 kΩ
4.19 kΩ
3.89 kΩ
3.61 kΩ
3.36 kΩ
3.12 kΩ
2.90 kΩ
2.70 kΩ
2.51 kΩ
2.33 kΩ
2.16 kΩ
2.00 kΩ
1.85 kΩ
1.71 kΩ
1.58 kΩ
1.45 kΩ
1.33 kΩ
1.22 kΩ
1.11 kΩ
1.00 kΩ
904 Ω
810 Ω
720 Ω
634 Ω
551 Ω
473 Ω
397 Ω
324 Ω
254 Ω
187 Ω
122 Ω
60 Ω
4
V O Adj
2
VIN
PTH05000W
Inhibit
CIN
330µF
(Required)
3
VO
5
VOUT
GND
1
RSET
0.1 W, 1 %
+
VIN
COUT
100µF
(Optional)
+
Inhibit
GND
GND
For technical support and more information, see inside back cover or visit www.ti.com
Notes:
1. Use a 0.1 W resistor. The tolerance should be 1 %,
with a 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 1
using dedicated PCB traces.
2. 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.
Application Notes
PTH05000 Series
Capacitor Recommendations for the PTH05000
Series of 6-A Power Modules
Input Capacitors
The recommended input capacitance is determined by
300 mA (rms) minimum ripple current rating, less than
300 mΩ equivalent series resistance (ESR) and 330 µF
minimum capacitance. The ripple current rating, ESR,
and operating temperature are the major considerations
when selecting the input capacitor.
It is recommended that tantalum capacitors have a minimum voltage rating of at least twice the working voltage,
including the ac ripple. This is necessary to insure reliability with 5-V input voltage bus applications.
Output Capacitors (optional)
The ESR of the output bulk (non-ceramic) capacitance
must be between 10 mΩ ≤ESR ≤200 mΩ. Electrolytic
capacitors have poor ripple performance at frequencies greater than 400 kHz but excellent low frequency
transient response. Above the ripple frequency, ceramic
decoupling capacitors are recommended to improve the
transient response and reduce any high frequency noise
components apparent during higher current excursions. A
maximum of 100 µF ceramic capacitance may be added to
the output bus.
Tantalum/ Ceramic Capacitors
Tantalum capacitors are acceptable on the output bus.
Either 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 at least the minimum
amount of capacitance. For the output bus, the total
amount of ceramic capacitance should be limited to 100 µF.
Capacitor Table
Table 1-1 identifies capacitors with acceptable ESR and
maximum allowable ripple current (rms) ratings. Capacitors recommended for the output are identified under
the Output Bus column with the required quantity.
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.
Table 1-1; Recommended Input/Output Capacitors
Capacitor Vendor/
Component
Series
Capacitor Characteristics
Quantity
Working
Voltage
Value (µF)
(ESR) Equivalent
Series Resistance
85°C Maximum
Ripple
Current (Irms)
Physical Size
(mm)
Input
Bus
Output
Bus
Panasonic WA (SMT)
FC
10 V
10 V
330 µF
330 µF
0.035 Ω
0.117 Ω
2800mA
555mA
8×6.9
8×11.5
1
1
1
1
EEFWA1A121P
EEUFC1A331
Panasonic FK (SMT)
16 V
25 V
330 µF
330 µF
0.160 Ω
0.160 Ω
600 mA
600 mA
8×10.2
8×10.2
1
1
1
1
EEVFK1C331P
EEVFK1E331P
United Chemi–con
PXA (SMT)
FS
LXZ (SMT)
MVZ
10 V
10 V
16 V
25 V
330 µF
330 µF
330 µF
330 µF
0.024 Ω
0.025 Ω
0.120 Ω
0.170 Ω
3770 mA
3500 mA
555 mA
450 mA
10×7.7
10×10.5
8×12
8×10
1
1
1
1
1
1
1
1
PXA10VC331MJ80TP
10FS330M
LXZ16VB331M8x12LL
MVZ25VC331MH10TP
Nichicon
UWG (SMT)
NA
PM
16V
10 V
10 V
330 µF
470 µF
330 µF
0.150 Ω
0.018 Ω
0.160 Ω
670 mA
>3100 mA
460 mA
10x10
10×10
8×11.5
1
1
1
1
1
1
UWG1C331MNR1GS
PNA1A471M1
UPM1A331MHH
Sanyo Os-con®
SVP (SMT)
SP
10 V
10 V
330 µF
470 µF
0.025 Ω
0.015 Ω
>3700 mA
>4500 mA
10×8
10×10.5
1
1
1
1
10SVP330MX
10SP470M
AVX Tantalum TPS
10 V
10 V
330 µF
330 µF
0.100 Ω
0.060 Ω
>1100 mA
>2000 mA
7.3L
×4.3W ×4.1H
1
1
1
1
TPSV337M010R0100
TPSV337M010R0060
Kemet T520
10 V
10 V
330 µF
330 µF
0.035 Ω
0.040 Ω
> 1200 mA
>1100 mA
7.3L ×5.7W
×4.0H
1
1
1
1
T510X337M010AS
T520X337M010AS
Sprague 594D/595D
10 V
10 V
330 µF
330 µF
0.045 Ω
0.140 Ω
>1400 mA
>1000 mA
7.3L
×6.0W ×4.1H
1
1
1
1
594D337X0010R2T
595D337X0010D2T
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
6
6
T495
Vendor Number
2 (max) C3225X5R0J476KT/MT
2 (max) GRM32ER60J476M/6.3
For technical support and more information, see inside back cover or visit www.ti.com
Application Notes
PTH03000 & PTH05000 Series
Power-Up Characteristics
When configured per their standard application, the
PTH03000 and PTH05000 series of power modules will
produce a regulated output voltage following the application of a valid input source voltage. During power up,
internal soft-start circuitry slows the rate that the output
voltage rises, thereby limiting the amount of in-rush
current that can be drawn from the input source. The
soft-start circuitry introduces a short time delay (typically 10 ms) into the power-up characteristic. This is
from the point that a valid input source is recognized.
Figure 3-1 shows the power-up waveforms for a PTH05000W
(5-V input), with the output voltage set point adjusted for a
2-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
Vin (2 V/Div)
Output On/Off Inhibit
For applications requiring output voltage on/off control,
the PTH03000W & PTH05000W power modules incorporate an output on/off Inhibit control (pin 3). The
inhibit feature can be used wherever there is a requirement for the output voltage from the regulator to be
turned off.
The power module functions 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. An
open-collector or open-drain device is recommended to
control this input.
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 the output voltage, following the turn-off of Q1. The turn off of
Q1 corresponds to the fall in the waveform, Q1 Vgs. The
waveforms were measured with a 5-A resistive load.
Vo (1 V/Div)
Figure 3-2
4
VO Adj
VIN =5 V
2
PTH05000W
Inhibit
+
HORIZ SCALE: 5 ms/Div
Current Limit Protection
The PTHxx000W modules protect against load faults
with a continuous current limit characteristic. Under a
load fault condition the output current cannot exceed
the current limit value. Attempting to draw current that
exceeds the current limit value causes the output voltage
to be progressively reduced. Current is continuously
supplied to the fault until it is removed. Upon removal of
the fault, the output voltage will promptly recover.
Thermal Shutdown
Thermal shutdown protects the module’s internal circuitry
against excessively high temperatures. A rise in temperature may be the result of a drop in airflow, a high ambient
temperature, or a sustained current limit condition. If
the junction temperature of the internal components
exceed 150 °C, the module will shutdown. This reduces
the output voltage to zero. The module will start up
automatically, by initiating a soft-start power up when
the sensed temperature decreases 10 °C below the thermal
shutdown trip point.
For technical support and more information, see inside back cover or visit www.ti.com
VO =2 V
5
VIN
CIN
330 µF
(Required)
Q1
BSS138
3
VO
GND
+
Iin (2 A/Div)
1
COUT
100 µF
(Optional)
4k87
0.1 W, 1 %
Inhibit
GND
GND
Figure 3-3
Vo (1 V/Div)
Q1 Vgs
(10 V/Div)
HORIZ SCALE: 5 ms/Div
L
O
A
D
Application Notes
PTH05000W
PTH05000W Startup with Output Pre-Bias
2. To ensure that the regulator does not sink current, the
input voltage must always be greater or equal to the
output voltage throughout the power-up and power-down
sequence.
A pre-bias startup condition occurs as a result of an external
voltage being present at the output of the power module
prior to its output voltage rising. 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 (to a higher supply voltage) as part of a
sequential power-up arrangement.
3. If during power up, the backfeeding source is greater
than the module’s set-point voltage, the module’s
output voltage will remain higher than its set point.
The output will remain out of regulation until the backfeeding source is either reduced in voltage or removed.
An output prebias can cause problems with power modules
that incorporate synchronous rectifiers. This is because
under most operating conditions, they can sink as well as
source ouput current. Although the PTH05000W (5-V
input) power module can sink current under normal operation, it will not do so during startup. 1 This is true as
long as certain conditions are maintained. 2 Figure 3-1
shows an application schematic that demonstrates this
capability. Figure 3-2 shows the waveforms of the circuit
after input power is applied. Note that the module’s output current (Io) is never negative. Only positive current
is sourced. This occurs when the output voltage is raised
above that which is backfed from the 5-V input supply, via
the diodes D1 through D4. 3
Figure 3-2; Start-up with Output Pre-Bias
Vin (1 V/Div)
Vo (1 V/Div)
Io (2 A/Div)
Notes
1. Start up includes both the application of a valid input
source voltage, or the removal of a ground signal from
the Inhibit* control (pin 3) with a valid input source
applied. The output of the regulator is effectively off
(tri-state), during the period that the Inhibit* control is
held low.
HORIZ SCALE: 5 ms/Div
Figure 3-1; Schematic Demonstrating Startup with Output Pre-Bias
D 1 - D4
MUR460
4
V O Adj
2
V IN
PTH05000W
Inhibit
3
CIN
330 µF
(Required)
VO
5
VO =2.5 V
GND
1
+
VIN =5 V
2k32
0.1 W, 1 %
C OUT
100 µF
(Optional)
L
O
A
D
0.55 Ω
Resistive
+
Inhibit
GND
GND
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