Bay Linear, Inc 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 989-7144, Fax: (925) 940-9556 www.baylinear.com
3.0A Low Dr opout Voltage Regulator B1085
Adjustable
Pin Connection
Ordering Information
Devices Package Temp.
B1085T TO-220
0 °C to 70 °C
B1085S TO-263
0 °C to 70 °C
B1085D TO-252
0 °C to 70 °C
Description
The Bay Linear B1085 is Monolithic low power 3.0A
Adjustable and fixed NPN voltage regulator that are easy to
use with minimum external components. All internal circuitry
is designed to operate down to 1V input to output differential
and the d ropout voltage is full y specified as a functio n of load
current. Dropout is guaranteed at a maximum of 1.5V at a
maximum output current. Current limit is trimmed, minimizing
the stress on both the regulator and power source circuitry
under overload conditions. It is suitable for applications
requiring a well-regulated positive output voltage with low
input-output dif ferentia l voltag e.
The B1085 Outstanding features include full power usage up
to 3.0Amp of load current internal current limiting and thermal
shutdown. A 10 µF output capacitor is required on these new
devices; how ever, this is usually included in most regulator
design.
The B1085 is offered in a 3-pin TO-220, TO-263 & TO-252
packages compatible with other 3 terminal regulators. For 5A
Low dropout Regulator refer to the BL1084 data sheet.
Features
• Adjustable Output Down to 1.2V
• Output Current of 3.0A
• Low Dropout Voltage 1.0V Typ.
• 0.015% Line Regulation
• 0.01% Load Regulation
• Current & Thermal Limiting
• Standard 3-Terminal Low Cost TO-220,
D2, D Packages
• Similar to industry Standard LT1085
Applications
• Constant Current Regulators
• SMPS Post Regulator
• High Efficiency Linear Regulator
• High Efficiency Linear Power Supplies
• Battery Charger
• Adjustable Po wer Supplies
Bay Linear
Bay LinearBay Linear
Bay Linear
Linea r Exc e lle nc e
Front View
TO-252 (D)
ADJ/
GND V
IN
V
OU
T
123
Top View
TO-263-3 (S)
1
Bay Linear
23
Top View
TO-263-3 (S)
1
Bay Linear
23
Top View
TO-263-3 (S)
1
Bay Linear
23
Top View
TO-263-3 (S)
1
Bay Linear
23
Bay Linear, Inc 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 989-7144, Fax: (925) 940-9556 www.baylinear.com
B1085
Absolute Maximum Rating
Parameter Symbol Value Unit
Maximum Input Voltage VIN 30 V
Power Dissipation PO Internally Limited W
Thermal Resistance Junction to Case θJC 3
Thermal Resistance Junction to
Ambient θJA 50 °C/W
Operating Junction
Temperature Range
Control Section
Power Transistor
TJ
0 to 125
0 to 150
Storage Temperature Range TSTG -65 to 150
Lead Temperature (Soldering 10
Sec.) TLEAD 300
°C
Electrical Characteristics
(VIN = 4.75V to 5.25V; IO = 10mA to 3.0Amp, unless otherwise specified)
Parameter Symbol Conditions MIN TYP MAX UNIT
1.238 1.262 Reference Vo ltage VO IO = 10mA,T= 25 °C, Vin-Vout =3V
10mA≤IOUT≤IFULL LOAD
1.5V≤(Vin-Vout) ≤25V (Note3)
1.225
1.250
1.270
V
Line Regulation (1) REG ( line) ILOAD = 10mA, 1.5V≤(VIN – VOUT) ≤15V
T= 25 °C
15V≤(Vin-Vout) ≤30V
0.015
0.035
0.05
0.20
0.20
0.50
Load Regulation (1) REG (LOAD) (Vin-Vout)=3V
10mA≤IOUT≤IFULL LOAD
T= 25 °C
0.1
0.2
0.30
0.40
%
Dropout V oltag e VD T= 25 °C
Over Temperature 1.3 1.5 V
Current Limit IS (Vin-Vout)=5V
(Vin-Vout)=25V 3.2
0.2 4
0.5 A
Mi ni mu m L o a d Cu r r e nt IMIN LOAD (Vin-Vout)= 25V 10 10 mA
Temperature Regulation T A T= 25 °C, 30m s pulse 0.004 0.02 %/W
Long Term Stability - T= 25 °C, 1000Hrs 0.3 1
Temperature Stability TS 0.5 %
Adjust pin Current - T= 25 °C
Over Temp. 55
120 µA
Ripple Rejection RA F=120Hz, CADJ=25µF, COUT=25µF Tantalum
IOUT=IFULL LO AD , (Vin-Vout)=3V (Note 5) 60 75 dB
Thermal Resistance - TO-220 Junction to Tab
Junction to Ambient
DD Package Junction to Tab
Junction to Ambient
3.0
60
3.0
60
3.0
60
3.0
60
°C/W
Note: Output Switch tests are performed under pulsed conditions to minimize power dissipation
Bay Linear, Inc 2478 Armstrong Street, Livermore, CA 94550 Tel: (925) 989-7144, Fax: (925) 940-9556 www.baylinear.com
Advance Information- These data sheets contain descriptions of products that are in development. The specifications are based on the engineering calculations,
computer simulations and/ or initial prototype evaluation.
Preliminary Information- These data sheets contain minimum and maximum specifications that are based on the initial device characterizations. These limits are
subject to change upon the completion of the full characterization over the specified temperature and supply voltage ranges.
The applicati on circuit examples ar e only to explain the representati ve applicatio ns of the devices and ar e not intended to guarantee any c ircuit
desi gn or permit any industrial prop erty right to other rights to execute. Bay Linear takes no responsibility for any prob lems related to any
industrial property right resulting from the use of th e conten ts shown in the data book. Typical parameters can and do vary in different
applications. Customer’s technical experts must validate all operating parameters including “ Typical” for each customer application.
LIFE SUPPORT AND NUCLEAR POLICY
Bay Linear products are not authorized for and should not be used within life support systems which are intended for surgical
implants into the body to support or sustain life, in aircraft, space eq uipment, submarine, or nuclear facility applications without
the specific written consent of Bay Linear President.
