DMOS
1A Low-Dropout Regulator
FEATURES
●NEW DMOS TOPOLOGY:
Ultra Low Dropout Voltage:
230mV typ at 1A and 3.3V Output
Output Capacitor NOT Required for Stability
●FAST TRANSIENT RESPONSE
●VERY LOW NOISE: 33µVRMS
●HIGH ACCURACY: ±2% max
●HIGH EFFICIENCY:
IGND = 1.7mA at IOUT = 1A
Not Enabled: IGND = 0.5µA
●2.5V, 2.7V, 3.0V, 3.3V, 5.0V AND
ADJUSTABLE OUTPUT VERSIONS
●THERMAL PROTECTION
●SMALL SURFACE-MOUNT PACKAGES:
SOT223-5, DDPAK-5
APPLICATIONS
●PORTABLE COMMUNICATION DEVICES
●BATTERY-POWERED EQUIPMENT
●MODEMS
●BAR-CODE SCANNERS
●BACKUP POWER SUPPLIES
DESCRIPTION
The REG104 is a family of low-noise, low-dropout linear
regulators with low ground pin current. Its new DMOS topol-
ogy provides significant improvement over previous designs,
including low dropout voltage (only 230mV typ at full load),
and better transient performance. In addition, no output
capacitor is required for stability, unlike conventional low
dropout regulators that are difficult to compensate and
require expensive low ESR capacitors greater than 1µF.
Typical ground pin current is only 1.7mA (at IOUT = 1A) and
drops to 0.5µA in
not enabled
mode. Unlike regulators with
PNP pass devices, quiescent current remains relatively con-
stant over load variations and under dropout conditions.
The REG104 has very low output noise (typically 33µVRMS
for VOUT = 3.3V with CNR = 0.01µF), making it ideal for use
in portable communications equipment. On-chip trimming
results in high output voltage accuracy. Accuracy is main-
tained over temperature, line, and load variations. Key pa-
rameters are tested over the specified temperature range
(–40°C to +85°C).
The REG104 is well protected—internal circuitry provides a
current limit which protects the load from damage. Thermal
protection circuitry keeps the chip from being damaged by
excessive temperature. The REG104 is available in the
DDPAK-5 and the SOT223-5.
REG104
REG104
REG104
(Fixed Voltage
Versions)
Enable
Gnd
0.1µFCOUT(1)
+
+VOUT
VIN
NR
NR = Noise Reduction
NOTE: (1) Optional.
REG104-A
Gnd
Enable
0.1µF
+COUT(1)
+
VOUT
VIN
R2
R1
Adj
REG104
SBVS025G – SEPTEMBER 2001 – REVISED SEPTEMBER 2005
www.ti.com
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of Texas Instruments
standard warranty. Production processing does not necessarily include
testing of all parameters.
Copyright © 2001-2005, Texas Instruments Incorporated
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.
All trademarks are the property of their respective owners.
SBVS025G
REG104
2
ABSOLUTE MAXIMUM RATINGS(1)
Supply Input Voltage, VIN .......................................................–0.3V to 16V
Enable Input Voltage, VEN....................................................... –0.3V to VIN
Feedback Voltage, VFB ........................................................ –0.3V to 6.0V
NR Pin Voltage, VNR .............................................................–0.3V to 6.0V
Output Short-Circuit Duration ......................................................Indefinite
Operating Temperature Range ....................................... –55°C to +125°C
Storage Temperature Range .......................................... –65°C to +150°C
Junction Temperature ..................................................... –55°C to +150°C
Lead Temperature (soldering, 3s, SOT, and DDPAK)................... +240°C
ESD Rating: HBM (VOUT to GND) ..................................................... 1.5kV
HBM (All other pins)........................................................ 2kV
CDM.............................................................................. 500V
NOTE: (1) Stresses above these ratings may cause permanent damage.
Exposure to absolute maximum conditions for extended periods may degrade
device reliability.
PIN CONFIGURATIONS
Top View
NOTE: (1) For REG104A-A: voltage setting resistor pin.
All other models: noise reduction capacitor pin.
Gnd
Enable
VIN
NR/Adjust(1)
VO
12345
DDPAK-5 SOT223-5
(KTT Package) (DCQ Package)
Tab is Gnd
Tab is Gnd
Enable
NR/Adjust(1)
GndVIN
12345
VOUT
ELECTROSTATIC
DISCHARGE SENSITIVITY
This integrated circuit can be damaged by ESD. Texas Instru-
ments recommends that all integrated circuits be handled with
appropriate precautions. Failure to observe proper handling
and installation procedures can cause damage.
ESD damage can range from subtle performance degradation
to complete device failure. Precision integrated circuits may be
more susceptible to damage because very small parametric
changes could cause the device not to meet its published
specifications.
PACKAGE/ORDERING INFORMATION(1)
PRODUCT VOUT
REG104xx-
yyyy/zzz
XX is package designator.
YYYY is typical output voltage (5 = 5.0V, 2.85 = 2.85V, A = Adjustable).
ZZZ is package quantity.
(1) For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI website at www.ti.com.
REG104 3
SBVS025G
REG104GA
REG104FA
PARAMETER CONDITION MIN TYP MAX UNITS
OUTPUT VOLTAGE
Output Voltage Range VOUT
REG104-2.5 2.5 V
REG104-2.7 2.7 V
REG104-3.0 3.0 V
REG104-3.3 3.3 V
REG104-5 5V
REG104-A VREF 5.5 V
Reference Voltage VREF 1.295 V
Adjust Pin Current IADJ 0.2 1 µA
Accuracy ±0.5 ±2%
TJ = –40°C to +85°C±3.0 %
vs Temperature dVOUT/dT TJ = –40°C to +85°C70ppm/°C
vs Line and Load IOUT = 10mA to 1A, VIN = (VOUT + 0.7V) to 15V ±0.5 ±2.5 %
TJ = –40°C to +85°CV
IN = (VOUT + 0.9V) to 15V ±3.5 %
DC DROPOUT VOLTAGE(2, 3) VDROP IOUT = 10mA 3 25 mV
For all models except 5V IOUT = 1A 230 400 mV
For 5V model IOUT = 1A 320 500 mV
For all models except 5V IOUT = 1A 480 mV
TJ = –40°C to +85°C
For 5V models IOUT = 1A 580 mV
TJ = –40°C to +85°C
VOLTAGE NOISE
f = 10Hz to 100kHz Vn
Without CNR (all models) CNR = 0, COUT = 0 35µVRMS/V • VOUT µVRMS
With CNR (all fixed voltage models) CNR = 0.01µF, COUT = 10µF10µVRMS/V • VOUT µVRMS
OUTPUT CURRENT
Current Limit(4) ICL 1.2 1.7 2.1 A
TJ = –40°C to +85°C1.0 2.2 A
RIPPLE REJECTION
f = 120Hz 65 dB
ENABLE CONTROL
VENABLE High (output enabled) VENABLE 2V
IN V
VENABLE Low (output disabled) –0.2 0.5 V
IENABLE High (output enabled) IENABLE VENABLE = 2V to VIN, VIN = 2.1V to 6.5(5) 1 100 nA
IENABLE Low (output disabled) VENABLE = 0V to 0.5V 2 100 nA
Output Disable Time 50 µs
Output Enable Softstart Time 1.5 ms
THERMAL SHUTDOWN
Junction Temperature
Shutdown 150 °C
Reset from Shutdown 130 °C
GROUND PIN CURRENT
Ground Pin Current IGND IOUT = 10mA 0.5 0.7 mA
IOUT = 1A 1.7 1.8 mA
Enable Pin Low VENABLE ≤ 0.5V 0.5 µA
INPUT VOLTAGE VIN
Operating Input Voltage Range(6) 2.1 15 V
Specified Input Voltage Range VIN > 2.7V VOUT + 0.7 15 V
TJ = –40°C to +85°CV
IN > 2.9V VOUT + 0.9 15 V
TEMPERATURE RANGE
Specified Range TJ–40 +85 °C
Operating Range –55 +125 °C
Storage Range –65 +150 °C
Thermal Resistance
DDPAK-5 Surface Mount
θ
JC Junction-to-Case 4 °C/W
SOT223-5 Surface Mount
θ
JC Junction-to-Case 15 °C/W
NOTES: (1) The REG104 does not require a minimum output capacitor for stability. However, transient response can be improved with proper capacitor selection.
(2) Dropout voltage is defined as the input voltage minus the output voltage that produces a 2% change in the output voltage from the value at VIN = VOUT + 1V
at fixed load.
(3) Not applicable for VOUT less than 2.7V.
(4) Current limit is the output current that produces a 15% change in output voltage from VIN = VOUT + 1V and IOUT = 10mA.
(5) For VIN > 6.5V, see typical characteristic
VENABLE vs IENABLE
.
(6) The REG104 no longer regulates when VIN < VOUT + VDROP (MAX). In drop-out or when the input voltage is between 2.7V and 2.1V, the impedance from VIN
to VOUT is typically less than 1Ω at TJ = +25°C. See typical characteristic
Output Voltage Change vs VIN
.
ELECTRICAL CHARACTERISTICS
Boldface limits apply over the specified temperature range, TJ = –40°C to +85°C
At TJ = +25°C, VIN = VOUT + 1V (VOUT = 3.0V for REG104-A), VENABLE = 2V, IOUT = 10mA, CNR = 0.01µF, and COUT = 0.1µF(1), unless otherwise noted.
SBVS025G
REG104
4
TYPICAL CHARACTERISTICS
For all models, at TJ = +25°C and VENABLE = 2V, unless otherwise noted.
0 200100 600500400300 700 800 900 1000
0.8
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
–1.2
Output Voltage Change (%)
Output Current (mA)
OUTPUT VOLTAGE CHANGE vs I
OUT
(V
IN
= V
OUT
+ 1V, Output Voltage % Change
Referred to I
OUT
= 10mA at +25°C)
+125°C
+25°C
–55°C
0 200 600400 800 1000
350
300
250
200
150
100
50
0
DC Dropout Voltage (mV)
IOUT (mA)
DC DROPOUT VOLTAGE vs IOUT
+125°C
+25°C
–55°C
–60 –40 –20 40 600 20 10080 120
0.6
0.4
0.2
0
–0.2
–0.4
–0.6
–0.8
–1
–1.2
Output Voltage (%)
Temperature (°C)
OUTPUT VOLTAGE CHANGE vs IOUT
(Output Voltage % Change Referred to
I
OUT
= 10mA at +25°C)
I
OUT
= 10mA
I
OUT
= 200mA
I
OUT
= 1000mA
–75 –50 –25 25 500 10075 125
350
300
250
200
150
100
50
0
DC Dropout Voltage (mV)
Temperature (°C)
DC DROPOUT VOLTAGE vs TEMPERATURE
I
OUT
= 1000mA
I
OUT
= 200mA
I
OUT
= 10mA
–75 –50 –25 25 500 10075 125
0.5
0.4
0.3
0.2
0.1
0
Output Voltage Change (%)
Temperature (°C)
LINE REGULATION vs TEMPERATURE
(V
IN
= V
OUT
+ 1V to 16V)
I
OUT
= 10mA
I
OUT
= 200mA
02 6841012
0.5
0
–0.5
–1
–1.5
–2
Output Voltage Change (%)
Input Voltage Above VOUT (V)
OUTPUT VOLTAGE CHANGE vs VIN
(Output Voltage % Change Referred to
VIN = VOUT + 1V at IOUT = 10mA)
I
OUT
= 10mA
I
OUT
= 1000mA
I
OUT
= 200mA
REG104 5
SBVS025G
TYPICAL CHARACTERISTICS (Cont.)
For all models, at TJ = +25°C and VENABLE = 2V, unless otherwise noted.
6V VIN
VOUT
VOUT
5V
50mV/div50mV/div
50µs/div
LINE TRANSIENT RESPONSE
COUT = 10µF
COUT = 0
REG104-3.3
IOUT = 200mA
1A ILOAD
VOUT
VOUT
10mA
500mV/div500mV/div
10µs/div
LOAD TRANSIENT RESPONSE
COUT = 10µF
COUT = 0 REG104-3.3
COUT = 0
REG104–A
CFB = 0.01µF, VOUT = 3.3V
COUT = 10µF
ILOAD
1A
10mA
LOAD TRANSIENT RESPONSE
10µs/div
500mV/div500mV/div
C
OUT
= 0
REG104–A
Load = 200mA, C
FB
= 0.01µF, V
OUT
= 3.3V
C
OUT
= 10µF
V
IN
6V
5V
LOAD TRANSIENT RESPONSE
50µs/div
50mV/div50mV/div
0.5
0.4
0.3
0.2
0.1
0
Output Voltage Change (%)
Temperature (°C)
LOAD REGULATION vs TEMPERATURE
(V
IN
= V
OUT
+ 1V and 10mA < I
OUT
< 1000mA)
–60 –40 –20 40 600 20 10080 120
10 100 1000 10000 100,000
10
5
2
1
0.5
0.2
0.1
0.05
0.02
0.01
Noise Density (µV/√Hz)
Frequency (Hz)
OUTPUT NOISE DENSITY
C
NR
= 0
C
OUT
= 0
C
NR
= 0.01µF
C
OUT
= 10µF
SBVS025G
REG104
6
TYPICAL CHARACTERISTICS (Cont.)
For all models, at TJ = +25°C and VENABLE = 2V, unless otherwise noted.
–60 –40 –20 0 20 40 60 80 120100
1.8
1.6
1.4
1.2
1
0.8
0.6
0.4
IGND (mA)
Temperature (°C)
GROUND PIN CURRENT vs TEMPERATURE
IOUT = 1000mA
IOUT = 200mA
IOUT = 10mA
–75 –50 –25 0 25 50 75 100 125
3
2.5
2
1.5
1
0.5
0
I
GND
(µA)
Temperature (°C)
GROUND PIN CURRENT, NOT ENABLED
vs TEMPERATURE
V
ENABLE
= 0V
1.6
1.4
1.2
1
0.8
0.6
0.4
I
GND
(mA)
I
OUT
(mA)
GROUND PIN CURRENT vs I
OUT
1 10010 1000
–20–40 0 40 80 120–60 20 60 100 140
0.28
0.26
0.24
0.22
0.20
0.18
0.16
0.14
Adjust Pin Current (µA)
Temperature (°C)
I
ADJUST
vs TEMPERATURE
REG104-A
1850
1800
1750
1700
1650
1600
1550
Current Limit (mA)
Temperature (°C)
CURRENT LIMIT vs TEMPERATURE
–60 –40 –20 40 600 20 10080 120
V
OUT
= V
OUT-NOMINAL
• 0.90
V
OUT
= 1V
10 100 1k 10k 100k
70
60
50
40
30
20
Ripple Rejection (dB)
Frequency (Hz)
RIPPLE REJECTION vs FREQUENCY
C
OUT
= 10µF
C
OUT
= 0
REG104 7
SBVS025G
TYPICAL CHARACTERISTICS (Cont.)
For all models, at TJ = +25°C and VENABLE = 2V, unless otherwise noted.
0 200 400 600 800 1000
75
70
65
60
55
50
45
40
Ripple Rejection (dB)
I
OUT
(mA)
RIPPLE REJECTION vs I
OUT
V
RIPPLE
= 3Vp-p, f = 120Hz
2V V
ENABLE
V
OUT
0
1V/div
250µs/div
SOFT START
2V
V
ENABLE
V
OUT
0
1V/div
10µs/div
OUTPUT DISABLE TIME
C
OUT
= 0
OUTPUT VOLTAGE DRIFT HISTOGRAM
Percent of Units (%)
V
OUT
Drift (ppm/°C)
40 45 50 55 60 65 70 75 80 85 90
45
40
35
30
25
20
15
10
5
0
OUTPUT VOLTAGE ACCURACY HISTOGRAM
Percent of Units (%)
Error (%)
–1–0.8 –0.6 –0.4 –0.2 0 0.2 0.4 0.6 0.8 1
60
50
40
30
20
10
0
SBVS025G
REG104
8
BASIC OPERATION
The REG104 series is a family of LDO (Low DropOut) linear
regulators. The family includes five fixed output versions
(2.5V to 5.0V) and an adjustable output version. An internal
DMOS power device provides low dropout regulation with
near constant ground pin current (largely independent of load
and dropout conditions) and very fast line and load transient
response. All versions include internal current limit and
thermal shutdown circuitry.
Figure 1 shows the basic circuit connections for the fixed
voltage models. Figure 2 gives the connections for the
adjustable output version (REG104A) and example resistor
values for some commonly used output voltages. Values for
other voltages can be calculated from the equation shown in
Figure 2.
FIGURE 1. Fixed Voltage Nominal Circuit for REG104.
REG104
Enable
VOUT
COUT
VIN
0.1µF
CNR
0.01µF
Gnd NR
In Out
Optional
FIGURE 2. Adjustable Voltage Circuit for REG104A.
VOUT = (1 + R1/R2) • 1.295V
Pin numbers for SOT-223 package.
REG104
VIN
0.1µF
3
1
Gnd
VOUT
R1CFB
0.01µFCOUT
Adj
R2
IADJ Load
2
4
5
Enable
To reduce current through divider, increase resistor
values (see table at right).
As the impedance of the resistor divider increases,
IADJ (~200nA) may introduce an error.
CFB improves noise and transient response.
VOUT (V) R1 (Ω)(1) R2 (Ω)(1)
1.295 Short Open
2.5 12.1k 13k
1.21k 1.3k
3 16.9k 13k
1.69k 1.3k
3.3 20k 13k
2.0k 1.3k
5 37.4k 13k
3.74k 1.3k
NOTE: (1) Resistors are standard 1% values.
EXAMPLE RESISTOR VALUES
Optional
Enable
V
Z
= 10V
175kΩ
FIGURE 3. Enable Pin Equivalent Input Circuit.
None of the versions require an output capacitor for regulator
stability. The REG104 will accept any output capacitor type
less than 1µF. For capacitance values larger than 1µF the
effective ESR should be greater than 0.1Ω. This minimum
ESR value includes parasitics such as printed circuit board
traces, solder joints, and sockets. A minimum 0.1µF low ESR
capacitor connected to the input supply voltage is recom-
mended.
ENABLE
The Enable pin allows the regulator to be turned on and off.
This pin is active HIGH and compatible with standard TTL-
CMOS levels. Inputs below 0.5V (max) turn the regulator off
and all circuitry is disabled. Under this condition ground-pin
current drops to approximately 0.5µA.
When not used, the Enable pin may be connected to VIN.
Internal to the part, the Enable pin is connected to an input
resistor-zener diode circuit, as shown in Figure 3, creating a
nonlinear input impedance.
REG104 9
SBVS025G
0 2 4 6 8 10 12 14 16
100
10
1
0.1
0.01
0.001
Enable Current (µA)
Enable Voltage
FIGURE 4. Enable Pin Current versus Applied Voltage.
The Enable Pin Current versus Applied Voltage relationship
is shown in Figure 4. When the Enable pin is connected to
VIN greater than 10V, a series resistor may be used to limit
the current.
FIGURE 5. Block Diagram.
FIGURE 6. Output Noise versus Noise Reduction Capacitor.
Since the value of V
REF
is 1.295V, this relationship reduces to:
VVVV
NRMS OUT
=µ•35
Connecting a capacitor, CNR, from the Noise-Reduction (NR)
pin to ground can reduce the output noise voltage. Adding
CNR, as shown in Figure 5, forms a low-pass filter for the
voltage reference. For CNR = 10nF, the total noise in the
10Hz to 100kHz bandwidth is reduced by approximately
a factor of 3.5. This noise reduction effect is shown in
Figure 6.
Over Current
Over Temp
Protection
VREF
(1.295V)
Low Noise
Charge Pump
DMOS
Output
R1
NOTE: R1 and R2 are internal
on fixed output versions.
VOUT
Adj
(Adjustable
Versions)
R2
NR
(fixed output
versions only)
Enable
REG104
VIN
CNR
(optional)
0.001 0.01 0.1 1
45
35
25
Output Noise Voltage
(µVRMS 10Hz - 100kHz)
CNR (µF)
COUT = 0
COUT = 10µF
REG104-3.3
OUTPUT NOISE
A precision band-gap reference is used for the internal
reference voltage, VREF, for the REG104. This reference is
the dominant noise source within the REG104. It generates
approximately 45µVRMS in the 10Hz to 100kHz bandwidth at
the reference output. The regulator control loop gains up the
reference noise, so that the noise voltage of the regulator is
approximately given by:
VV
RR
RVV
V
NRMS RMS OUT
REF
=µ +=µ •45 245
12
The REG104 adjustable version does not have the noise-
reduction pin available, however, the adjust pin is the
summing junction of the error amplifier. A capacitor, CFB,
SBVS025G
REG104
10
connected from the output to the adjust pin will reduce both
the output noise and the peak error from a load transient.
Figure 7 shows improved output noise performance for two
capacitor combinations.
FIGURE 7. Output Noise Density on Adjustable Versions.
FIGURE 8. Transient and DC Dropout.
For large step changes in load current, the REG104 requires
a larger voltage drop across it to avoid degraded transient
response. The boundary of this
transient dropout
region is
shown as the top line in Figure 8. Values of VIN to VOUT
voltage drop above this line insure normal transient re-
sponse.
In the transient dropout region between
DC
and
Transient
,
transient response recovery time increases. The time re-
quired to recover from a load transient is a function of both
the magnitude and rate of the step change in load current
and the available
headroom
VIN to VOUT voltage drop. Under
worst-case conditions (full-scale load change with VIN to
VOUT voltage drop close to DC dropout levels), the REG104
can take several hundred microseconds to re-enter the
specified window of regulation.
TRANSIENT RESPONSE
The REG104 response to transient line and load conditions
improves at lower output voltages. The addition of a capaci-
tor (nominal value 10nF) from the output pin to ground may
improve the transient response. In the adjustable version, the
addition of a capacitor, CFB (nominal value 10nF), from the
output to the adjust pin will also improve the transient
response.
THERMAL PROTECTION
Power dissipated within the REG104 will cause the junction
temperature to rise. The REG104 has thermal shutdown
circuitry that protects the regulator from damage. The ther-
mal protection circuitry disables the output when the junc-
tion temperature reaches approximately 150°C, allowing
the device to cool. When the junction temperature cools to
approximately 130°C, the output circuitry is again enabled.
Depending on various conditions, the thermal protection
circuit may cycle on and off. This limits the dissipation of the
regulator, but may have an undesirable effect on the load.
Any tendency to activate the thermal protection circuit indi-
cates excessive power dissipation or an inadequate heat
sink. For reliable operation, junction temperature should be
limited to 125°C, maximum. To estimate the margin of safety
in a complete design (including heat sink), increase the
ambient temperature until the thermal protection is triggered.
Use worst-case loads and signal conditions. For good reli-
ability, thermal protection should trigger more than 35°C
above the maximum expected ambient condition of your
application. This produces a worst-case junction temperature
of 125°C at the highest expected ambient temperature and
worst-case load.
The internal protection circuitry of the REG104 has been
designed to protect against overload conditions. It was not
intended to replace proper heat sinking. Continuously run-
ning the REG104 into thermal shutdown will degrade reliabil-
ity.
250
200
150
100
50
0
Drop Out Voltage (mV)
0 100 200 300 400 500
IOUT (mA)
REG104 –3.3 at 25°C
DC
Transient
10010 1000 10000 100000
10.0
1.0
0.1
nV/√Hz
Frequency
COUT = 0, CFB = 0
COUT = 0, CFB = 0.01µF
COUT = 10µF, CFB = 0.01µF
The REG104 utilizes an internal charge pump to develop an
internal supply voltage sufficient to drive the gate of the
DMOS pass element above VIN. The charge-pump switching
noise (nominal switching frequency = 2MHz) is not measur-
able at the output of the regulator.
DROP-OUT VOLTAGE
The REG104 uses an N-channel DMOS as the
pass
ele-
ment. When the input voltage is within a few hundred
millivolts of the output voltage, the DMOS device behaves
like a resistor. Therefore, for low values of VIN to VOUT, the
regulator’s input-to-output resistance is the RdsON of the
DMOS pass element (typically 230mΩ). For static (DC)
loads, the REG104 will typically maintain regulation down to
VIN to VOUT voltage drop of 230mV at full rated output current.
In Figure 8, the bottom line (DC dropout) shows the minimum
VIN to VOUT voltage drop required to prevent dropout under
DC load conditions.
REG104 11
SBVS025G
FIGURE 9. Maximum Power Dissipation versus Ambient
Temperature for the Various Packages and
PCB Heat Sink Configurations.
POWER DISSIPATION
The REG104 is available in two different package configura-
tions. The ability to remove heat from the die is different for
each package type and, therefore, presents different consid-
erations in the printed circuit board (PCB) layout. The PCB
area around the device that is free of other components
moves the heat from the device to the ambient air. While it
is difficult to impossible to quantify all of the variables in a
thermal design of this type, performance data for several
configurations are shown in Figure 9. In all cases the PCB
copper area is bare copper, free of solder resist mask, and
not solder plated. All examples are for 1-ounce copper. Using
heavier copper will increase the effectiveness in moving the
heat from the device. In those examples where there is
copper on both sides of the PCB, no connection has been
provided between the two sides. The addition of plated
through holes will improve the heat sink effectiveness.
Power dissipation depends on input voltage and load condi-
tions. Power dissipation is equal to the product of the aver-
age output current times the voltage across the output
element, VIN to VOUT voltage drop.
PVV I
DIN
OUT OUT AVG
=•(–)()
Power dissipation can be minimized by using the lowest
possible input voltage necessary to assure the required
output voltage.
5
4
3
2
1
0
Power Dissipation (Watts)
0 25 50 75 125100
Ambient Temperature (°C)
CONDITIONS
#1
#2
#3
#4
CONDITION PACKAGE PCB AREA
θ
JA
1 DDPAK 4in2 Top Side Only 27°C/W
2 SOT-223 4in2 Top Side Only 53°C/W
3 DDPAK None 65°C/W
4 SOT-223 0.5in2 Top Side Only 110°C/W
SBVS025G
REG104
12
FIGURE 10. Thermal Resistance versus PCB Area for the Five-Lead DDPAK.
FIGURE 11. Thermal Resistance versus PCB Area for the Five Lead SOT-223.
50
40
30
20
10
0
Thermal Resistance, θJA (°C/W)
012345
Copper Area (inches2)
REG104
Surface Mount Package
1 oz. copper
Circuit Board Copper Area
REG104
DDPAK Surface Mount Package
THERMAL RESISTANCE vs PCB COPPER AREA
THERMAL RESISTANCE vs PCB COPPER AREA
180
160
140
120
100
80
60
40
20
0
Thermal Resistance, JA (°C/W)
θ
012345
Copper Area (inches2)
Circuit Board Copper Area
REG104
SOT-223 Surface Mount Package
REG104
Surface Mount Package
1 oz. copper
REGULATOR MOUNTING
The tab of both packages is electrically connected to ground.
For best thermal performance, the tab of the DDPAK sur-
face-mount version should be soldered directly to a circuit-
board copper area. Increasing the copper area improves
heat dissipation. Figure 10 shows typical thermal resistance
from junction to ambient as a function of the copper area for
the DDPAK. Figure 11 shows the same relationship for the
SOT-223.
Although the tabs of the DDPAK and the SOT-223 are
electrically grounded, they are not intended to carry any
current. The copper pad that acts as a heat sink should be
isolated from the rest of the circuit to prevent current flow
through the device from the tab to the ground pin. Solder pad
footprint recommendations for the various REG104 devices
are presented in the Application Bulletin
Solder Pad Recom-
mendations for Surface-Mount Devices
(SBFA015A), avail-
able from the Texas Instruments web site (www.ti.com).
PACKAGE OPTION ADDENDUM
www.ti.com 17-Aug-2012
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status (1) Package Type Package
Drawing Pins Package Qty Eco Plan (2) Lead/
Ball Finish MSL Peak Temp (3) Samples
(Requires Login)
REG104FA-2.5 OBSOLETE DDPAK/
TO-263 KTT 5 TBD Call TI Call TI
REG104FA-2.5/500 ACTIVE DDPAK/
TO-263 KTT 5 500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-2.5/500G3 ACTIVE DDPAK/
TO-263 KTT 5 500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-2.5KTTT ACTIVE DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-2.5KTTTG3 ACTIVE DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-2.7 OBSOLETE DDPAK/
TO-263 KTT 5 TBD Call TI Call TI
REG104FA-3 OBSOLETE DDPAK/
TO-263 KTT 5 TBD Call TI Call TI
REG104FA-3.3 OBSOLETE DDPAK/
TO-263 KTT 5 TBD Call TI Call TI
REG104FA-3.3/500 ACTIVE DDPAK/
TO-263 KTT 5 500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-3.3/500G3 ACTIVE DDPAK/
TO-263 KTT 5 500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-3.3KTTT ACTIVE DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-3.3KTTTG3 ACTIVE DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-3/500 NRND DDPAK/
TO-263 KTT 5 TBD Call TI Call TI
REG104FA-3/500G3 NRND DDPAK/
TO-263 KTT 5 TBD Call TI Call TI
REG104FA-3KTTT NRND DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-3KTTTG3 NRND DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-5 OBSOLETE DDPAK/
TO-263 KTT 5 TBD Call TI Call TI
PACKAGE OPTION ADDENDUM
www.ti.com 17-Aug-2012
Addendum-Page 2
Orderable Device Status (1) Package Type Package
Drawing Pins Package Qty Eco Plan (2) Lead/
Ball Finish MSL Peak Temp (3) Samples
(Requires Login)
REG104FA-5/500 ACTIVE DDPAK/
TO-263 KTT 5 500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-5/500G3 ACTIVE DDPAK/
TO-263 KTT 5 500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-5KTTT ACTIVE DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-5KTTTG3 ACTIVE DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-A OBSOLETE DDPAK/
TO-263 KTT 5 TBD Call TI Call TI
REG104FA-A/500 ACTIVE DDPAK/
TO-263 KTT 5 500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-A/500G3 ACTIVE DDPAK/
TO-263 KTT 5 500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-AKTTT ACTIVE DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104FA-AKTTTG3 ACTIVE DDPAK/
TO-263 KTT 5 50 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104GA-2.5 ACTIVE SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-2.5/2K5 ACTIVE SOT-223 DCQ 6 2500 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-2.5/2K5G4 ACTIVE SOT-223 DCQ 6 2500 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-2.5G4 ACTIVE SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-3 NRND SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-3.3 ACTIVE SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-3.3/2K5 ACTIVE SOT-223 DCQ 6 2500 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-3.3/2K5G4 ACTIVE SOT-223 DCQ 6 2500 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-3.3G4 ACTIVE SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
PACKAGE OPTION ADDENDUM
www.ti.com 17-Aug-2012
Addendum-Page 3
Orderable Device Status (1) Package Type Package
Drawing Pins Package Qty Eco Plan (2) Lead/
Ball Finish MSL Peak Temp (3) Samples
(Requires Login)
REG104GA-3G4 NRND SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU NIPDAU Level-2-260C-1 YEAR
REG104GA-5 ACTIVE SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104GA-5/2K5 ACTIVE SOT-223 DCQ 6 2500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104GA-5/2K5G4 ACTIVE SOT-223 DCQ 6 2500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104GA-5G4 ACTIVE SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104GA-A ACTIVE SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104GA-A/2K5 ACTIVE SOT-223 DCQ 6 2500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104GA-A/2K5G4 ACTIVE SOT-223 DCQ 6 2500 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
REG104GA-AG4 ACTIVE SOT-223 DCQ 6 78 Green (RoHS
& no Sb/Br) CU SN Level-2-260C-1 YEAR
(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), Pb-Free (RoHS Exempt), 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.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
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.
PACKAGE OPTION ADDENDUM
www.ti.com 17-Aug-2012
Addendum-Page 4
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
TAPE AND REEL INFORMATION
*All dimensions are nominal
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
REG104FA-2.5/500 DDPAK/
TO-263 KTT 5 500 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104FA-2.5KTTT DDPAK/
TO-263 KTT 5 50 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104FA-3.3/500 DDPAK/
TO-263 KTT 5 500 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104FA-3.3KTTT DDPAK/
TO-263 KTT 5 50 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104FA-3KTTT DDPAK/
TO-263 KTT 5 50 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104FA-5/500 DDPAK/
TO-263 KTT 5 500 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104FA-5KTTT DDPAK/
TO-263 KTT 5 50 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104FA-A/500 DDPAK/
TO-263 KTT 5 500 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104FA-AKTTT DDPAK/
TO-263 KTT 5 50 330.0 24.4 10.6 15.6 4.9 16.0 24.0 Q2
REG104GA-2.5/2K5 SOT-223 DCQ 6 2500 330.0 12.4 6.8 7.3 1.88 8.0 12.0 Q3
REG104GA-3.3/2K5 SOT-223 DCQ 6 2500 330.0 12.4 6.8 7.3 1.88 8.0 12.0 Q3
REG104GA-5/2K5 SOT-223 DCQ 6 2500 330.0 12.4 6.8 7.3 1.88 8.0 12.0 Q3
PACKAGE MATERIALS INFORMATION
www.ti.com 17-Aug-2012
Pack Materials-Page 1
Device Package
Type Package
Drawing Pins SPQ Reel
Diameter
(mm)
Reel
Width
W1 (mm)
A0
(mm) B0
(mm) K0
(mm) P1
(mm) W
(mm) Pin1
Quadrant
REG104GA-A/2K5 SOT-223 DCQ 6 2500 330.0 12.4 6.8 7.3 1.88 8.0 12.0 Q3
*All dimensions are nominal
Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm)
REG104FA-2.5/500 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0
REG104FA-2.5KTTT DDPAK/TO-263 KTT 5 50 367.0 367.0 45.0
REG104FA-3.3/500 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0
REG104FA-3.3KTTT DDPAK/TO-263 KTT 5 50 367.0 367.0 45.0
REG104FA-3KTTT DDPAK/TO-263 KTT 5 50 367.0 367.0 45.0
REG104FA-5/500 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0
REG104FA-5KTTT DDPAK/TO-263 KTT 5 50 367.0 367.0 45.0
REG104FA-A/500 DDPAK/TO-263 KTT 5 500 367.0 367.0 45.0
REG104FA-AKTTT DDPAK/TO-263 KTT 5 50 367.0 367.0 45.0
REG104GA-2.5/2K5 SOT-223 DCQ 6 2500 358.0 335.0 35.0
REG104GA-3.3/2K5 SOT-223 DCQ 6 2500 358.0 335.0 35.0
REG104GA-5/2K5 SOT-223 DCQ 6 2500 358.0 335.0 35.0
REG104GA-A/2K5 SOT-223 DCQ 6 2500 358.0 335.0 35.0
PACKAGE MATERIALS INFORMATION
www.ti.com 17-Aug-2012
Pack Materials-Page 2