SEMTECH EZ1581CT-2.5

DUAL INPUT
LOW DROPOUT REGULATOR
February 26, 1999
EZ1580/EZ1581
EZ1582/EZ1583
TEL:805-498-2111 FAX:805-498-3804 WEB:http://www.semtech.com
DESCRIPTION
The EZ158X family of high performance positive
voltage regulators are designed for use in applications
requiring very low dropout voltage at 7, 5, 3 and 1.5
amps. When supplying 2.5V on motherboards where
both 5V and 3.3V supplies are available, the superior
dropout characteristics of the EZ158X result in reduced
heat dissipation compared to regular LDOs, thus
allowing heat sink size reduction. Additionally, the
EZ158X provides excellent regulation over variations in
line, load and temperature. Remote sense operation
allows compensating for trace, connector and other
resistive losses.
Outstanding features include very low dropout
performance at rated current, fast transient response,
remote sense, internal current limiting, thermal
shutdown and safe operating area protection of the
output device. The EZ158X is a five terminal
adjustable voltage regulator available in the popular 5
pin TO-220 and TO-263 plastic packages.
ORDERING INFORMATION
DEVICE
PACKAGE IOUT (A)
EZ1580CT-X.X
TO-220,
7
EZ1581CT-X.X
5-pin
5
See Note (1)
EZ1582CT-X.X
3
EZ1583CT-X.X
1.5
EZ1580CM-X.X
TO-263,
7
EZ1581CM-X.X
5-pin(2)
5
VOUT (V)
See Note (1)
EZ1582CM-X.X
3
EZ1583CM-X.X
1.5
Notes:
(1) Where -X.X denotes voltage options. Available
voltages are: 1.5V and 2.5V. Leave blank for adjustable version (1.3 to 5.7V).
(2) Add suffix ‘TR’ for tape and reel (TO-263).
FEATURES
ABSOLUTE MAXIMUM RATINGS
•= 540mV dropout @ 7A in dual supply mode
Parameter
•=
•=
•=
•=
(EZ1580)
Remote sense operation
Fast transient response
0.5% initial accuracy
5 Pin TO-220 and TO-263 packages
APPLICATIONS
•=
•=
•=
•=
•=
Microprocessor supplies
Split plane microprocessor supplies
Pentium® Processor P54C and P55C
PowerPC™ 603/604EV
AMD5K86™, AMD K6
BLOCK DIAGRAM
Input Voltage
VPOWER
VCONTROL
Power
Dissipation
Thermal Resistance
Junction to Case
EZ1580/1 TO-220
EZ1580/1 TO-263
EZ1582/3 TO-220
EZ1582/3 TO-263
Thermal Resistance
Junction to Ambient
EZ158X TO-220
EZ158X TO-263
Operating Junction
Temperature Range
Storage Temperature
Range
Lead Temperature
(Soldering) 10 Sec.
Symbol
Maximum
Units
VP
VC
7
13.2
V
PD
Internally
Limited
W
θJC
2
2
3
3
°C/W
θJA
50
60
°C/W
TJ
0 to 125
°C
TSTG
-65 to 125
°C
TLEAD
260
°C
Pentium is a registered trademark of Intel Corporation.
PowerPC is a trademark of IBM.
AMD5K86 and K6 are trademarks of Advanced Micro Devices.
© 1999 SEMTECH CORP.
1
652 MITCHELL ROAD NEWBURY PARK CA 91320
DUAL INPUT
LOW DROPOUT REGULATOR
EZ1580/EZ1581
EZ1582/EZ1583
February 26, 1999
PIN CONFIGURATION
PIN DESCRIPTION
Pin Pin Name
1
2
SENSE
Pin Function
This pin is the positive side of the reference voltage for this device. With this pin it is possible to
Kelvin sense the output voltage at the load.
ADJUST / This pin is the negative side of the reference voltage for the device. Transient response can be
improved by adding a small bypass capacitor from the adjust pin to ground.
GROUND This pin is the bottom end of the internal resistor feedback chain for fixed output voltage parts,
and should be connected to ground.
3
4
5
OUTPUT
This is the power output of the device, and is electrically connected to the TAB.
CONTROL This pin is the supply pin for the control circuitry for the device. The current flow into this pin will
be approximately 1% of the output current. For the device to regulate, the voltage at this pin must
be between 1.0V and 1.3V greater than the output voltage (see dropout specifications).
POWER
This is the collector input to the power device of the EZ158X. The output load current is supplied
through this pin. For the device to regulate, the voltage on this pin must be between 0.1V and
0.7V greater than the output voltage, depending upon load current (see dropout specifications).
2
© 1999 SEMTECH CORP.
652 MITCHELL ROAD NEWBURY PARK CA 91320
DUAL INPUT
LOW DROPOUT REGULATOR
EZ1580/EZ1581
EZ1582/EZ1583
February 26, 1999
ELECTRICAL CHARACTERISTICS
Test Conditions
Parameter
Reference Voltage
Symbol
VCNTL
Volts
VPWR
Volts
Amps
VREF
2.75
2.00
0.01
25°C
1.243
1.250
1.257
2.7 - 12
2.05 - 5.5
O.T.
1.237
1.250
1.263
V
O.T.
1.0
3.0
mV
O.T.
1.0
5.0
mV
O.T.
5.0
10
mA
120
mA
120
µA
Line Regulation
REG(LINE)
2.5 - 12
1.75 - 5.5
Load Regulation
EZ1583
EZ1582
EZ1581
EZ1580
REG(LOAD)
2.75
2.1
IO
5
3.3
IC
2.75
2.05
Adjust Pin Current
IADJ
2.75
2.05
Current Limit
EZ1583
EZ1582
EZ1581
EZ1580
ICL
2.75
2.05
Ripple Rejection (4)
EZ1583
EZ1582
EZ1581
EZ1580
RA
3.75
3.75
Control Pin Current
EZ1583
EZ1582
EZ1581
EZ1580
0.01 - 1.5
0.01 - 3.0
0.01 - 5.0
0.01 - 7.0
0.01
0.01 - 1.5
0.01 - 3.0
0.01 - 5.0
0.01 - 7.0
Min
Typ
Max
Units
(3)
Thermal Regulation (5)
Dropout Voltage
Minimum VCNTL
EZ1583
EZ1582
EZ1581
EZ1580
Test Limits
(6)
TJ
EZ1583
EZ1582
EZ1581
EZ1580
Minimum Load Current (2)
(1)
1.5
3.0
5.0
7.0
0.01
O.T.
O.T.
0.75
1.5
2.5
3.5
6.0
30
33
60
O.T.
25°C
REG(THERMAL)
50
1.6
3.1
5.1
7.1
60
A
80
dB
0.002
0.02
1.00
1.05
1.10
1.15
1.15
1.18
1.25
1.30
%/W
(7)
VC-VO
2.05
1.5
3.0
5.0
7.0
O.T.
V
Dropout Voltage (7)
Minimum VPOWER
EZ1583
1.5
25°C
O.T.
0.40
0.50
0.50
0.60
3.0
25°C
O.T.
0.40
0.50
0.50
0.60
EZ1581
5.0
25°C
O.T.
0.40
0.50
0.50
0.60
EZ1580
7.0
25°C
O.T.
0.54
0.70
0.62
0.80
EZ1582
NOTES
VP-VO
2.75
(1) Unless otherwise specified, VOUT = VSENSE, VADJ = 0V.
(2) Required to maintain regulation. Voltage set resistors R1, R2 are usually utilized for minimum load current.
(3) Current used to drive the output section; minimum value equals the standby current of the device.
(4) VC = VP = 3.75V Avg; VRIPPLE = 1VPK-PK.
(5) 30ms.
(6) Over Temp (O.T.) = over specified operating junction temperature range.
(7) Minimum input/output voltage required to maintain 1% regulation.
© 1999 SEMTECH CORP.
V
3
652 MITCHELL ROAD NEWBURY PARK CA 91320
DUAL INPUT
LOW DROPOUT REGULATOR
EZ1580/EZ1581
EZ1582/EZ1583
February 26, 1999
TYPICAL APPLICATIONS
Adjustable Output Parts
(1)(2)
(3)
U1
3.3V POWER IN
5
5V CONTROL IN
4
EZ158XCX
1
SENSE
VREF
POWER
3
OUTPUT
2.5V OUT
CONTROL
ADJ
C1
33uF
C2
10uF
R1
124
C3
68uF
2
R2
124
GROUND
GROUND
VOUT
R2 ö
æ
= VREF ç 1 +
+ I ADJ • R 2
R1
è
Fixed Output Parts
U1
EZ158XCX-2.5
1
SENSE
3.3V POWER IN
5
5V CONTROL IN
4
POWER
OUTPUT
3
2.5V OUT
CONTROL
GND
C1
33uF
C2
10uF
C3
68uF
2
GROUND
GROUND
U1
EZ158XCX-1.5
1
SENSE
2.5V POWER IN
5
3.3V CONTROL IN
4
POWER
OUTPUT
3
1.5V OUT
CONTROL
GND
C1
47uF
GROUND
C2
10uF
2
C3
100uF
GROUND
NOTES:
(1) Capacitor values are for reference only. Good quality, low ESR tantalum or aluminum electrolytic capacitors
should be used. Increasing the value of the output capacitor will improve the overall transient response.
(2) If the same voltage is input to both POWER and CONTROL, then the dropout voltage will become 1.3V maximum.
(3) A small (~0.033µF) capacitor can be used to bypass the ADJUST pin to improve transient response, if needed.
4
© 1999 SEMTECH CORP.
652 MITCHELL ROAD NEWBURY PARK CA 91320
DUAL INPUT
LOW DROPOUT REGULATOR
EZ1580/EZ1581
EZ1582/EZ1583
February 26, 1999
APPLICATION INFORMATION
DEVICE OUTLINE - TO-220, 5 PIN
The EZ158X is a low dropout regulator designed to
power the next generation of low voltage, split voltage
plane processors, such as the Pentium® Processor
P55C, the IBM PowerPC™ 603EV and 604EV and the
AMD5K86™ and K6 Processors.
The dropout voltage is minimized by utilizing a
separate input voltage, VCONTROL, which should exceed
VOUT by at least 1.3V. The 2.5V power for the load
(microprocessor core) can be derived from a 3.3V
system supply. Since the efficiency of a linear regulator
is the ratio of the output to the input voltage, heat
dissipation is reduced by using a 3.3 input, thereby
lowering heatsink and cooling fan costs. For a load of
7A at 2.5V, the regulator would dissipate 17.5W when
converting from 5V, but only 5.6W from a 3.3V input.
Remote Kelvin sensing of the output voltage can be
achieved by connecting the sense pin to the output at
the load. Remote sensing will reduce errors
associated with resistive trace losses between
regulator and processor.
DEVICE OUTLINE - TO-263, 5 PIN
MINIMUM LAND PATTERN - TO-263, 5 PIN
5
© 1999 SEMTECH CORP.
652 MITCHELL ROAD NEWBURY PARK CA 91320