EUTECH EUP7961

EUP7961
1A Ultra Low-Dropout Linear Regulator
DESCRIPTION
FEATURES
The EUP7961 is a 1A low-dropout linear regulator that
provides a low voltage, high current output with a
minimum of external components. It offers high
precision, ultra-low dropout, and low ground current.
The EUP7961 operates from an input of 2.5V to 5.5V.
This regulator uses small, 1µF ceramic input capacitors
and 4.7µF ceramic output capacitors to deliver 1A
output current. High bandwidth provides excellent
transient response. It is designed to drive digital
circuits requiring low voltage at high currents (i.e.,
PLDs, DSPs, microcontrollers, etc.).
Other features include thermal and current limit
protection, a logic-control shutdown mode and an error
flag output that goes low when the output voltage
drops 10% below nominal value.
It is available in fixed output voltages of 1.5V, 1.8V,
2.5V, 3.3V and as an adjustable device with a 0.8V
reference voltage. The adjustable output voltage can be
set from 0.8V to 4.5V.
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APPLICATIONS
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Typical Application Circuit
Figure1.
DS7961 Ver 1.2 Dec. 2006
1A Guaranteed Output Current
300mV Dropout Voltage at 1A Output
Stable with Ceramic Capacitors
±1.8% Output Voltage Accuracy
300µA Low-Ground Pin Current
0.1µA Quiescent Current in Shutdown Mode
Excellent Line and Load Regulation
Thermal Shutdown and Current Limit Protection
Error Flag Indication
Available in SOT223, SOP-8 and SOT-89 Packages
RoHS Compliant and 100% Lead (Pb)-Free
1
LDO Linear Regulator for Low-Voltage Digital IC
PC Add-In Cards
High Efficiency Linear Power Supplies
Post Regulator
EUP7961
Block Diagram
Figure2.
Pin Configurations
Package
Type
Package
Type
Pin Configurations
SOT223-3
SOT223-3 (B)
SOT-89
SOP-8
Pin Configurations
Pin Description
PIN
SOT-223
VEN
-
SOT-223
(B)
-
VIN
1
GND
VOUT
ERROR
SOT-89
SOP-8
-
1
Enable Input. Logic high=enable, Logic low=shutdown
3
3
2
Input Voltage of the LDO
2
1
2
5,6,7,8
3
2
1
3
-
4
-
ADJ
DS7961 Ver 1.2 Dec. 2006
-
DESCRIPTION
Ground: TAB is connected to ground
Output voltage of the LDO
ERROR Flag Output. Active-low indicated an output fault
condition
Adjustable Regulator Feedback Input. Connect to resistor
voltage divider
2
EUP7961
Ordering Information
Order Number
Package Type
EUP7961-15BIR1
SOT223
EUP7961-18BIR1
SOT223
EUP7961-25BIR1
SOT223
EUP7961-33BIR1
SOT223
EUP7961B-15BIR1
SOT223
EUP7961B-18BIR1
SOT223
EUP7961B-25BIR1
SOT223
EUP7961B-33BIR1
SOT223
EUP7961-15CIR1
SOT-89
EUP7961-18CIR1
SOT-89
EUP7961-25CIR1
SOT-89
EUP7961-33CIR1
SOT-89
EUP7961-15DIR1
SOP-8
EUP7961-18DIR1
SOP-8
EUP7961-25DIR1
SOP-8
EUP7961-33DIR1
SOP-8
EUP7961DIR1
SOP-8
Marking
Operating Temperature range
xxxx
P7961C
xxxx
P7961D
xxxx
P7961B
xxxx
P7961H
xxxx
7961CB
xxxx
7961DB
xxxx
7961BB
xxxx
7961HB
xxxx
P7961C
xxxx
P7961D
xxxx
P7961B
xxxx
P7961H
xxxx
EUP7961
C
xxxx
EUP7961
D
xxxx
EUP7961
B
xxxx
EUP7961
H
xxxx
EUP7961
A
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
-40 °C to 125°C
EUP7961- □ □ □ □ □ □
Lead Free Code
1: Lead Free 0: Lead
Packing
R: Tape & Reel
Operating temperature range
I: Industry Standard
Package Type:
B: SOT223 C: SOT89
Output Voltage
DS7961 Ver 1.2 Dec. 2006
3
D: SOP
EUP7961
Absolute Maximum Ratings
Supply Voltage VIN ---------------------------------------------------------------------- 5.5V
Package Thermal Resistance
SOT-223, θJA ---------------------------------------------------------------------- 115°C /W
SOP-8, θJA ------------------------------------------------------------------------- 125°C /W
Power Dissipation, PD@TA=25°C
SOT-223 ------------------------------------------------------------------------------ 0.87W
SOP-8 --------------------------------------------------------------------------------- 0.8W
Junction Temperature ------------------------------------------------------------------- 150°C
Storage Temperature ------------------------------------------------------ -65°C to +150°C
Lead Temp -----------------------------------------------------------------------------260°C
ESD Rating
Human Body Model ---------------------------------------------------------------------- 2kV
„
„
„
„
„
„
„
Operating Ratings
„
„
„
Supply Voltage VIN ---------------------------------------------------------------- 2.5 to 5.5V
Enable Input Voltage -------------------------------------------------------------- 0V to 5.5V
Junction Temperature ------------------------------------------------------ -40°C to +125°C
Electrical Characteristics
Limits in standard typeface are for TJ =25°C. Unless otherwise specified: VIN= VOUT(nom) +1V, IL=10mA,COUT=4.7µF
Symbol
ΔVOUT
Parameter
Output Voltage Tolerance
VOUT+1V ≤ VIN ≤ 5.5V
10mA ≤ IL ≤ 1A
Line Regulation
VOUT+1V ≤ VIN ≤ 5.5V
Load Regulation
10mA ≤ IL ≤ 1A
VIN -VOUT Dropout Voltage
IGND
IO(PK)
Conditions
Ground Pin Current in
Normal Operation Mode
EUP7961
Typ
Max.
%
0.1
0.24
%
0.08
0.32
%
IL = 100mA
35
50
IL = 1A
300
500
IL = 10mA
300
IL = 1A
500
VEN ≤ 0.3V
Peak Output Current
VO ≥ VO(NOM) -4%
-1.8
Unit
1.8
Ground Pin Current in
Shutdown Mode
0.01
Short Circuit Protection
ISC
Short Circuit Current
DS7961 Ver 1.2 Dec. 2006
Min
4
mV
µA
10
µA
1.5
A
1.7
A
EUP7961
Electrical Characteristics
Limits in standard typeface are for TJ =25°C. Unless otherwise specified: VIN= VOUT(nom) +1V, IL=10mA,COUT=4.7µF
Symbol
VIH
Parameter
Enable Threshold
VIL
Conditions
Output = High
EUP7961
Min
Typ
Max.
1.4
VIN
Output = Low
0
TdOFF
Turn-off delay
IL = 1A
20
TdON
Turn-on delay
IL = 1A
20
VEN Pin Input Current
VEN=VIN
0.1
IEN
ERROR
VT
Flag
Threshold
VTH
VEF(Sat)
Td
IIK
Imax
Threshold Hysteresis
Flag Saturation
Flag Reset Delay
ERROR
ERROR
Flag Pin Leakage
ERROR
Flag Pin Sink
en
Ripple Rejection
Output Noise Voltage
VError=0.5V
VIN=VOUT+1V
COUT=10uF
VOUT=3.3V, f=120Hz
BW=10Hz -100kHz
VOUT=2.5V
V
µs
1
µA
10
%
5
%
0.02
Current
Current
AC Parameters
PSRR
ISINK=100µA
0.3
Unit
0.1
V
1
µs
1
nA
3.8
mA
60
dB
150
µV(rms)
150
°C
10
°C
Over Temperature Protection
TSH(t)
TSH(h)
Shutdown Threshold
Thermal Shutdown
Hysteresis
DS7961 Ver 1.2 Dec. 2006
5
EUP7961
Typical Operating Characteristics
DS7961 Ver 1.2 Dec. 2006
6
EUP7961
DS7961 Ver 1.2 Dec. 2006
7
EUP7961
Application Note
External Capacitors
Like any low-dropout regulator, the EUP7961 requires
external capacitors for regulator stability. These
capacitors must be correctly selected for good
performance.
Input Capacitor
An input capacitance of 1µF is required between the
EUP7961 input pin and ground (the amount of the
capacitance may be increased without limit).
This capacitor must be located a distance of not more
than 1cm from the input pin and returned to a clean
analog ground. Any good quality ceramic, tantalum, or
film capacitor may be used at the input.
If a tantalum capacitor is used at the input, it must be
guaranteed by the manufacturer to have a surge current
rating sufficient for the application.
There are no requirements for the ESR on the input
capacitor, but tolerance and temperature coefficient must
be considered when selecting the capacitor to ensure the
capacitance will be 1µF over the entire operating
temperature range.
Output Capacitor
The EUP7961 is designed specifically to work with very
small ceramic output capacitors. A ceramic capacitor
(temperature characteristics X7R, X5R, Z5U, or Y5V) in
4.7 to 22µF range with 5mΩ to 200mΩ ESR range is
suitable in the EUP7961 application circuit.
The output capacitor must meet the requirement for
minimum amount of capacitance and also have an ESR
(Equivalent Series Resistance) value which is within a
stable range (5mΩ to 200mΩ)
No-Load Stability
The EUP7961 will remain stable and in regulation with
no external load. This is specially important in CMOS
RAM keep-alive applications.
On/Off Input Operation
The EUP7961 is turned off by pulling the VEN pin low,
and turned on by pulling it high. If this feature is not used,
the VEN pin should be tied to VIN to keep the regulator
output on at all time. To assure proper operation, the
signal source used to drive the VEN input must be able
to swing above and below the specified turn-on/off
voltage thresholds listed in the Electrical Characteristics
section under VIL and VIH.
DS7961 Ver 1.2 Dec. 2006
8
ERROR Flag Operation
The EUP7961 produces a logic low signal at the
ERROR Flag pin when the output drops out of
regulation due to low input voltage, current limiting, or
thermal limiting. This flag has a built in hysteresis.
The internal ERROR flag comparator has an open drain
output stage. Hence, the ERROR pin should be pulled
high through a pull up resistor. The ERROR pin must be
connected to ground if this function is not used. It should
also be noted that when the shutdown pin is pulled low,
the ERROR pin is forced to be invalid for reasons of
saving power in shutdown mode.
Adjustable Operation
The adjustable version of the EUP7961 has an output
voltage range of 0.8V to 4.5V. The output voltage of the
EUP7961 adjustable regulator is programmed using an
external resistor divider as shown in Figure3. The output
voltage is calculated using:
V =V
O
ref
× (1 +
R1
R
)
2
Where:
Vref= 0.8V typ. (the internal reference voltage)
Utilize the following equation for adjusting the output to
a particular voltage:
 V

PI = R  O − 1
2 0.8V


Choose R2=50k to optimize accuracy, power supply
rejection, noise and power consumption.
EUP7961
Power Dissipation
EUP7961 can deliver a continuous current of 2A over the
full operating temperature range. A heatsink may be
required depending on the maximum power dissipation
and maximum ambient temperature of the application.
Under all possible conditions, the junction temperature
must be within the range specified under operating
conditions. The total power dissipation of the device is
given by:
(
)
( )
P = V −V
I
+ V
I
D
IN
IN GND
OUT OUT
Where IGND is the operating ground current of the device
(specified under Electrical Characteristics).
The maximum allowable temperature rise (TRmax)
depends on the maximum ambient temperature (TAmax)
of the application, and the maximum allowable junction
temperature (TJmax):
TRmax= TJmax-TAmax
The maximum allowable value for junction to ambient
Thermal Resistance, θJA , can be calculated using the
formula:
θJA =TRmax/PD
DS7961 Ver 1.2 Dec. 2006
9
PCB Layout
Good PC layout practices must be used or instability can
be induced because of ground loops and voltages drops.
The input and output capacitors must be directly
connected to the input, output, and ground pins of the
regulator using traces which do not have other currents
flowing in them.
The best way to do this is to lay out CIN and COUT near
the device with short traces to the VIN, VOUT, and ground
pins. The regulator ground pin should be connected to
the external circuit ground so that the regulator and its
capacitors have a “single point ground”.
It should be noted that stability problems have been seen
in applications where “vias” to an internal ground plane
were used at the ground points of the IC and the input
and output capacitors. This was caused by varying
ground potentials at these nodes resulting from current
flowing through the ground plane. Using a single point
ground technique for the regulator and it’s capacitors
fixed the problem.
Since high current flows through the traces going into
VIN and coming from VOUT, Kelvin connect the capacitor
leads to these pins so there is no voltage drop in series
with the input and output capacitors.
EUP7961
Packaging Information
SOT223-3
SYMBOLS
A
A1
B
B1
D
E
e
H
L
DS7961 Ver 1.2 Dec. 2006
MILLIMETERS
MIN.
MAX.
1.50
1.80
0.00
0.10
0.60
0.80
2.90
3.10
6.50
3.50
2.30
6.70
7.30
0.80
1.10
10
INCHES
MIN.
0.059
0.000
0.024
0.114
MAX.
0.071
0.004
0.031
0.122
0.256
0.138
0.090
0.264
0.031
0.287
0.043
EUP7961
SOP-8
SYMBOLS
A
A1
D
E1
E
L
b
e
DS7961 Ver 1.2 Dec. 2006
MILLIMETERS
MIN.
MAX.
1.35
1.75
0.05
0.25
4.90
3.90
5.80
6.20
0.40
1.27
0.33
0.51
1.27
11
INCHES
MIN.
0.053
0.002
0.193
0.153
0.228
0.016
0.013
0.500
MAX.
0.069
0.010
0.244
0.050
0.020
EUP7961
SOT-89
SYMBOLS
A
L
B1
B
C
D
D1
H
E
e
DS7961 Ver 1.2 Dec. 2006
MILLIMETERS
MIN.
MAX.
1.40
1.60
0.89
1.20
0.36
0.48
0.44
0.56
0.35
0.44
4.40
4.60
1.35
1.83
3.94
4.25
2.29
2.60
1.50
12
INCHES
MIN.
0.055
0.035
0.014
0.017
0.014
0.173
0.053
0.155
0.090
0.059
MAX.
0.063
0.047
0.019
0.022
0.017
0.181
0.072
0.167
0.102