LD1085
SERIES
3A LOW DROP FIXED AND ADJUSTABLE
POSITIVE VOLTAGE REGULATORS
May 2000
BLOCKDIAGRAM
D2PAK
■TYPICALDROPOUT VOLTAGE1.3V AT 3A
■THREE TERMINAL ADJUSTABLEOR FIXED
OUTPUTVOLATGE1.8V,2.5V,2.85V,3.3V,
3.6V,5V,8V, 9V, 12V
■GUARANTEED OUTPUT CURRENT UP TO
3A
■OUTPUTTOLERANCE±1%AT 25oC AND
±2% IN FULL TEMPERATURE RANGE
■INTERNALPOWERAND THERMALLIMIT
■WIDE OPERATING TEMPERATURE RANGE
-40oC TO125oC
■PACKAGEAVAILABLE:TO-220D2PAK
■PINOUT COMPATIBILITYWITHSTANDARD
ADJUSTABLEVOLTAGEREGULATORS
DESCRIPTION
The LD1085 is a LOW DROP Voltage Regulator
able to provide up to 3A of Output Current.
Dropout is guaranteed at a maximum of 1.5V at
the maximum output current, decreasing at
lower loads. The LD1085 is pin compatible with
older 3-terminal adjustable regulators, but has
better performances in term of drop and output
tolerance. A 2.85V output version is suitable for
SCSI-2 active termination. Unlike PNP
regulators, where a part of the output current is
wasted as quiescent current, the LD1085
quiescent current flow into the load, so increase
efficency. Only a 10 µF minimum capacitor is
need for stability. The device is supplied in
TO-220, D2PAK and D2PAK/A packages. On
chip trimming allows the regulator to reach a
very tight output voltage tolerance, within ±1%
at 25oC.
TO-220
D2PAK/A
1/15
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
VIN DC Input Voltage 30 V
IOUT OutputCurrent Internally Limited mA
Ptot PowerDissipation Internally Limited mW
Tstg Storage Temperature Range -50 to 150 oC
Top Operating Junction Temperature Range -40 to 125 oC
Absolute Maximum Ratings are those value beyond which damage to the device may occur. Functional operation under these condition is
not implied. Over the above suggested Max PowerDissipation a ShortCircuit could definetively damage the device.
THERMALDATA
Symbol Parameter TO-220 D2PAK Unit
Rthj-case
Rthj-amb Thermal Resistance Junction-case
Thermal Resistance Junction-ambient 3
50 3
62.5
oC/W
oC/W
APPLICATION CIRCUIT FOR FIXED AND ADJUSTABLE VERSION
CONNECTION DIAGRAM AND ORDERING NUMBERS (top view)
TO-220 D2PAK (**) D2PAK/A (**) Output Voltage
LD1085V18
LD1085V25
LD1085V28
LD1085V33
LD1085V36
LD1085V50
LD1085V80
LD1085V90
LD1085V120
LD1085D2T18
LD1085D2T25
LD1085D2T28
LD1085D2T33
LD1085D2T36
LD1085D2T50
LD1085D2T80
LD1085D2T90
LD1085D2T120
LD1085D2M18
LD1085D2M25
LD1085D2M28
LD1085D2M33
LD1085D2M36
LD1085D2M50
LD1085D2M80
LD1085D2M90
LD1085D2M120
1.8V
2.5V
2.85V
3.3V
3.6V
5V
8V
9V
12V
LD1085V LD1085D2T LD1085D2M 1.25 to 28V
(**)Availablein Tape & Reel with the suffix ”R” for fixed version and ”-R” for adjustableversion.
TO-220 D2PAK D2PAK/A
VO=
V
REF
(1+
R
2
R
1)
LD1085 SERIES
2/15
ELECTRICAL CHARACTERISTICS FOR LD1085#25(refer to the test circuits,
Tj= -40to 125 oC, VIN = 5.5V, CIN =C
O=10µF unlessotherwisespecified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25oC 2.475 2.5 2.525 V
VOOutputVoltage(Note 1) IO= 0 to3 A Vin = 4.1to 30 V 2.45 2.5 2.55 V
∆VOLineRegulation Vin =4.1to 18 V IO= 0 mA Tj=25o
C0.25mV
∆
V
O
LineRegulation Vin =4.1to 18 V IO=0mA 0.4 5 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C210mV
∆
V
O
LoadRegulation IO= 0 to3 A 4 20 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent Vin ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
V
in =7.5 ±3V 60 72 dB
eN Output Noise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
ELECTRICAL CHARACTERISTICS FOR LD1086#18(refer to the test circuits,
Tj= -40to 125 oC, VIN = 4.8V, CIN =C
O=10µF unlessotherwisespecified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25oC 1.782 1.8 1.818 V
VOOutputVoltage(Note 1) IO= 0 to3 A VIN = 3.4to 30V 1.764 1.8 1.836 V
∆VOLineRegulation VIN =3.4 to18 V IO= 0 mA Tj=25o
C0.24mV
∆
V
O
LineRegulation VIN =3.4 to18 V IO=0mA 0.4 4 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C210mV
∆
V
O
LoadRegulation IO= 0 to3 A 4 20 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent VIN ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
V
IN =5.3 ±1V 60 75 dB
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
LD1085 SERIES
3/15
ELECTRICAL CHARACTERISTICS FOR LD1085#285(refer to the test circuits,
Tj= -40to 125 oC, VIN = 5.85V, CIN =C
O=10µF unlessotherwise specified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25oC 2.821 2.85 2.879 V
VOOutputVoltage(Note 1) IO= 0 to3 A VIN = 4.5to 30V 2.793 2.85 2.907 V
∆VOLineRegulation VIN =4.5to 18V IO= 0 mA Tj=25o
C0.26mV
∆
V
O
LineRegulation VIN =4.5to 18V IO=0mA 0.5 6 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C315mV
∆
V
O
LoadRegulation IO= 0 to3 A 7 20 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent VIN ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
V
IN = 7.85 ±3V 60 72 dB
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
ELECTRICAL CHARACTERISTICS FOR LD1085#33(refer to the test circuits,
Tj= -40to 125 oC, VIN = 6.3V, CIN =C
O=10µF unlessotherwisespecified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25oC 3.267 3.3 3.333 V
VOOutputVoltage(Note 1) IO= 0 to3 A VIN = 4.9to 30V 3.234 3.3 3.366 V
∆VOLineRegulation VIN =4.9to 18V IO= 0 mA Tj=25o
C0.56mV
∆
V
O
LineRegulation VIN =4.9to 18V IO=0mA 1 6 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C315mV
∆
V
O
LoadRegulation IO= 0 to3 A 7 20 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent VIN ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
V
IN =8.3 ±3V 60 72 dB
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
LD1085 SERIES
4/15
ELECTRICAL CHARACTERISTICS FOR LD1085#36(refer to the test circuits,
Tj= -40to 125 oC, VIN = 5.85V, CIN =C
O=10µF unlessotherwise specified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25oC 3.564 3.6 3.636 V
VOOutputVoltage(Note 1) IO= 0 to3 A VIN = 5.2to 30V 3.528 3.6 3.672 V
∆VOLineRegulation VIN =5.2to 18V IO= 0 mA Tj=25o
C0.510mV
∆
V
O
LineRegulation VIN =5.2to 18V IO= 0 mA 1 10 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C315mV
∆
V
O
LoadRegulation IO= 0 to3 A 7 20 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent VIN ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
V
IN =8.6 ±3V 60 72 dB
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
ELECTRICAL CHARACTERISTICS FOR LD1085#50(refer to the test circuits,
Tj= -40to 125 oC, VIN = 8 V, CIN =C
O=10µF unless otherwisespecified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25oC4.9555.05V
V
O
OutputVoltage(Note 1) IO= 0 to3 A VIN = 6.6to 30V 4.9 5 5.1 V
∆VOLineRegulation VIN =6.6to 20V IO= 0 mA Tj=25o
C0.510mV
∆
V
O
LineRegulation VIN =6.6to 20V IO= 0 mA 1 10 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C520mV
∆
V
O
LoadRegulation IO= 0 to3 A 10 35 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent VIN ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
V
IN =10±3V 60 72 dB
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
LD1085 SERIES
5/15
ELECTRICAL CHARACTERISTICS FOR LD1085#80(refer to the test circuits,
Tj= -40to 125 oC, VIN =11V, C
IN =C
O=10µF unlessotherwisespecified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25oC7.9288.08V
V
O
OutputVoltage(Note 1) IO= 0 to3 A VIN =9.8to 30 V 7.84 8 8.16 V
∆VOLineRegulation VIN =9.8to 20V IO= 0 mA Tj=25o
C118mV
∆
V
O
LINeRegulation VIN = 9.8to 20 V IO= 0mA 2 18 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C830mV
∆
V
O
LoadRegulation IO= 0 to3 A 12 60 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent VIN ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
V
IN =13±3V 54 71 dB
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
ELECTRICAL CHARACTERISTICS FOR LD1085#90(refer to the test circuits,
Tj= -40to 125 oC, VIN =12V, C
IN =C
O=10µF unlessotherwisespecified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25o
C8.9199.09V
V
O
OutputVoltage(Note 1) IO= 0 to3 A VIN =11to30V 8.82 9 9.18 V
∆VOLineRegulation VIN =11to20V I
O=0 mA Tj=25oC120mV
∆
V
O
LineRegulation VIN =11to20V I
O=0 mA 2 20 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C830mV
∆
V
O
LoadRegulation IO= 0 to3 A 12 60 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent VIN ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
VIN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f= 120 Hz CO=25µF
V
IN =14±3V 54 70 dB
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000hrs Ta=125o
C0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
LD1085 SERIES
6/15
ELECTRICAL CHARACTERISTICS FOR LD1085#120(refer to the test circuits,
Tj= -40to 125 oC, VIN =15V, C
IN =C
O=10µF unlessotherwisespecified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO= 0 mA Tj=25oC 11.88 12 12.12 V
VOOutputVoltage(Note 1) IO= 0 to3 A VIN = 13.8 to 30 V 11.76 12 12.24 V
∆VOLineRegulation VIN =13.8to 25 V IO= 0 mA Tj=25o
C125mV
∆
V
O
LineRegulation VIN =13.8to 25 V IO= 0 mA 2 25 mV
∆VOLoadRegulation IO= 0 to3 A Tj=25o
C1236mV
∆
V
O
LoadRegulation IO= 0 to3 A 24 72 mV
VdDropout Voltage IO=3A 1.3 1.5 V
IdQuiescentCurrent VIN ≤30 V 5 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.008 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
V
IN =17±3V 54 66 dB
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
ELECTRICAL CHARACTERISTICS FOR LD1085 (refer to the test circuits,
Tj= -40to 125 oC, VIN = 4.25V, CIN =C
O=10µF unlessotherwise specified)
Symbol Parameter Test Conditions Min. Typ. Max. Unit
VOOutputVoltage IO=10mA T
j=25o
C 1.237 1.25 1.263 V
VOOutputVoltage(Note 1) IO= 0.01 to 3 A VIN =2.8 to 30 V 1.225 1.25 1.275 V
∆VOLineRegulation VIN =2.75to 16.5V IO=10mA Tj=25oC 0.015 0.2 %
∆VOLineRegulation VIN =2.75to 16.5V IO=10mA 0.035 0.2 %
∆VOLoadRegulation IO= 0.01 to 3 A Tj=25o
C0.10.3%
∆
V
O
LoadRegulation IO= 0.01 to 3 A 0.2 0.4 %
VdDropout Voltage IO=3A 1.3 1.5 V
IO(min) Minimum Load Current VIN =30V 3 10 mA
ISC Short Circuit Current VIN -VO=5V
V
IN -VO=25V 3.2
0.2 4.5
0.5 A
Thermal Regulation Ta=25o
C 30msPulse 0.01 0.04 %/W
SVR Supply Voltage Rejection IO= 3 A f = 120 Hz CO=25µF
C
ADJ =25
µFV
IN = 6.25±3V 60 75 dB
IADJ Adjust pinCurrent IO=10mA V
IN =4.25V 55 120 µA
∆IADJ Adjust pinCurrent Change VIN =2.75to 16.5V IO= 0.01to 3A 0.2 5 µA
eN OutputNoise Voltage B = 10Hzto 10KHz Ta=25o
C 0.003 %
S Temperature Stability 0.5 %
S Long TermStability 1000 hrs Ta= 125oC0.5%
Note1: See short-circuit curve for available output current at fixed dropout.
LD1085 SERIES
7/15
TYPICALCHARACTERISTICS (unless otherwise specifiedTJ=125oC, CIN=CO=10µF)
Output Voltage vs Temperature Output Voltage vs Temperature
Output Voltage vs Temperature
Line Regulationvs Temperature
Short Circuit Current vs Dropout Voltage
LoadRegulationvs Temperature
LD1085 SERIES
8/15
Dropout Voltage vs Temperature
AdjustPin Currentvs Temperature
QuiescentCurrent vs OutputCurrent
Dropout Voltagevs OutputCurrent
QuiescentCurrent vs Temperature
SupplyVoltage Rejectionvs OutputCurrent
TYPICALCHARACTERISTICS (Continued)
LD1085 SERIES
9/15
SupplyVoltage Rejectionvs Frequency
MinimumLoad Currentvs Temperature
Stability
SupplyVoltage Rejectionvs Temperature
Stability
TYPICALCHARACTERISTICS (Continued)
LD1085 SERIES
10/15
Line Transient
LoadTransient
Line Transient
LoadTransient
TYPICALCHARACTERISTICS (Continued)
LD1085 SERIES
11/15
DIM. mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
A 4.40 4.60 0.173 0.181
C 1.23 1.32 0.048 0.051
D 2.40 2.72 0.094 0.107
D1 1.27 0.050
E 0.49 0.70 0.019 0.027
F 0.61 0.88 0.024 0.034
F1 1.14 1.70 0.044 0.067
F2 1.14 1.70 0.044 0.067
G 4.95 5.15 0.194 0.203
G1 2.4 2.7 0.094 0.106
H2 10.0 10.40 0.393 0.409
L2 16.4 0.645
L4 13.0 14.0 0.511 0.551
L5 2.65 2.95 0.104 0.116
L6 15.25 15.75 0.600 0.620
L7 6.2 6.6 0.244 0.260
L9 3.5 3.93 0.137 0.154
DIA. 3.75 3.85 0.147 0.151
L6
A
C
D
E
D1
F
G
L7
L2
Dia.
F1
L5
L4
H2
L9
F2
G1
TO-220 MECHANICAL DATA
P011C
LD1085 SERIES
12/15
DIM. mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
A 4.4 4.6 0.173 0.181
A1 2.49 2.69 0.098 0.106
B 0.7 0.93 0.027 0.036
B2 1.14 1.7 0.044 0.067
C 0.45 0.6 0.017 0.023
C2 1.23 1.36 0.048 0.053
D 8.95 9.35 0.352 0.368
E 10 10.4 0.393 0.409
G 4.88 5.28 0.192 0.208
L 15 15.85 0.590 0.624
L2 1.27 1.4 0.050 0.055
L3 1.4 1.75 0.055 0.068
L2 L3
L
B2 B
G
E
A
C2
D
C
A1
DETAIL”A” DETAIL”A”
A2
P011P6/F
TO-263 (D2PAK) MECHANICALDATA
LD1085 SERIES
13/15
DIM. mm inch
MIN. TYP. MAX. MIN. TYP. MAX.
A 4.4 4.6 0.173 0.181
A1 2.49 2.69 0.098 0.106
B 0.7 0.93 0.027 0.036
B2 1.14 1.7 0.044 0.067
C 0.45 0.6 0.017 0.023
C2 1.21 1.36 0.047 0.053
D 8.95 9.35 0.352 0.368
E 10 10.4 0.393 0.409
G 4.88 5.28 0.192 0.208
L 15 15.85 0.590 0.624
L2 1.27 1.4 0.050 0.055
D2PAK/A MECHANICAL DATA
LD1085 SERIES
14/15
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LD1085 SERIES
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