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SI91860
Vishay Siliconix
400-mA Smart Regulator for Network Interface Card
FEATURES
D D D D D D D D Single Fixed 3.3-V Output Linear Regulator for Dual Power Inputs Auxilliary Input Can Be Bypassed Automatically Switches Between Linear Regulator and Bypass Mode Linear Regulator: 3.3-V "3% Output at 400-mA Current Linear Regulator: 600-mA Peak Output Current Low Bypass Switch Drop: <55-mV Drop at 150 mA Built-in Short Circuit and Thermal Shutdown Protection D Low Supply Current D SOIC-8 Package
APPLICATIONS
D D D D Network Interface Cards (NIC) PCMCIA Cards Cardbus Desktop Computers/Workstations
DESCRIPTION
The SI91860 provides a constant 3.3-V output with multiple inputs. This function is required in many power interface applications, such as the Network Interface Card (NIC). The SI91860 is offered in small SOIC-8 package with up to 2-W Power handling capability. The complete application circuit uses only four external components. to 3.3 V. A 200-m power switch is integrated to connect the 3.3-VAUX input to the output. The power drawn priority is 5 VIN > 5 VSB > 3.3 VAUX, where the selection is done internally and automatically by the SI91860. The power handling capability is as such as to carry at least 400-mA continuous load current for any power input condition. In order to satisfy the stringent ambient temperature requirements in many applications, the SI91860 is rated for the industrial temperature range of -40_C to 85_C. The SI91860 is available in both standard and lead (Pb)-free packages.
The PCI Card has a 3.3-V Chipset while the PCI bus has two independent 5-V sources. When needed, the two 5-V sources are available from the PCI bus or directly from the motherboard--normally 5 VIN and standby 5 VSB. The internal regulator steps down from either of the 5-V supplies
FUNCTIONAL BLOCK DIAGRAM
SI91860
5 VSB
5 VIN
Regulator and Control
3.3 VOUT
3.3 VAUX
GND
Document Number: 71340 S-40704--Rev. B, 19-Apr-04
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SI91860
Vishay Siliconix
ABSOLUTE MAXIMUM RATINGS
Pin 1, 2, 4 Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to 6 V Linear Regulator Output Current (peak) . . . . . . . . . . . . . . . . . . . . . . . . 600 mA Bypass Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 600 mA Maximum Junction Temperature, TJ(max) . . . . . . . . . . . . . . . . . . . . . . . . 150_C Storage Temperature, TSTG . . . . . . . . . . . . . . . . . . . . . . . . . . -55_C to 150_C ESD (Human Body Model) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 kV Package Power Dissipationb PD . . . . . . . . . . . . . . . . . . . . . . . . 2W (internally limited via thermal shutdown) Thermal Impedance (qJA)a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62.5_C/W Notes a. Device mounted with all leads soldered or welded to PC board. b. Derate 16 mW/_C above TA = 25_C
Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
RECOMMENDED OPERATING RANGE
5-VIN and 5-VSB Pin Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4.5 V to 5.5 V 3.3-VAUX Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 V to 3.6 V Load Range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 mA to 400 mA Operating Ambient Temperature, TA . . . . . . . . . . . . . . . . . . . . -40_C to 85_C
SPECIFICATIONS
Test Conditions Unless Otherwise Specified Parameter Regulator Mode
Output Voltage (Regulator) 5 VIN Select Rising Edge of Hysteresis 5 VSB Select Ground Pin Current In Regulator MODEd Peak Output Current (Regulator) Output Noise Voltage (Regulator) IGND IO eN D3.3 D3 3 VOUT/ D5 VIN DVO(line) DVO(load) tON TJ(s/d) THYST ISC 3.3 VOUT = 0 V IO = 0 mA IO = 400 mA tPW = 2 ms BW = 50 Hz to100 kHz, IOUT = 150 mA 1 kHz Ripple Rejection (Regulator) pp j (g ) IOUT = 150 mA 10 kHz 100 kHz VIN: 4.5 V to 5.5 V tR/tF = 2 ms, IOUT = 150 mA IOUT: 1 mA to 150 mA, tR/tF = 2 ms VO(LDO) 0 mA < IOUT < 400 mA, 4.5 V < 5 VIN 5 VSB < 5.5 V Threshold Hysteresis Threshold Hysteresis Full Full Full Full Full Full Full Full Room Room Room Room Room Room Room Full Full Room 600 300 60 40 30 10 20 15 165 20 900 mA ms _C C mV dB mV(rms) 3.201 3.3 4.30 230 4.30 230 0.3 0.7 0.8 1.6 mA 4.475 3.399 4.475 mV V mV V
Limits
-40 to 85_C
Symbol
5 VIN = 5 VSB = 5 V, 3 VAUX = 3 30 V V 3.30 IOUT = 1 mA, CIN = 4.7 mF, COUT = 2.2 mF
Tempa
Minb
Typc
Maxb
Unit
Dynamic Line Regulation Dynamic Load Regulation VOUT Turn-On-Time Thermal Shutdown Junction Temperature Thermal Hysteresis Short Circuit Current
Bypass Mode (5 VIN = 5 VSB = GND)
Output Voltage Bypass Switch On-Resistance Ground Currentd VO(BP) rDS(on) IGND 0 mA < IOUT < 150 mA 3.0 V v VAUX v 3.6 V 0 mA < IOUT < 400 mA Full Full Full 3.247 0.2 200 0.35 400 V W mA
Notes a. Room = 25_C, Full = -40 to 85_C. b. The algebraic convention whereby the most negative value is a minimum and the most positive a maximum. c. Typical values are for DESIGN AID ONLY, not guaranteed nor subject to production testing. Typical values at 25_C ambient. d. Ground pin current includes the IC supply current and the current to drive the linear regulator or bypass switch. www.vishay.com Document Number: 71340 S-40704--Rev. B, 19-Apr-04
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SI91860
Vishay Siliconix
TIMING WAVEFORMS
5V
tON
VIN 0.95 VOUT
VOUT
FIGURE 1. Timing Diagram
PIN CONFIGURATION
SO-8
5 VSB 5 VIN 3.3 VOUT 3.3 VAUX 1 2 3 4 Top View 8 7 6 5 GND GND GND GND
PIN DESCRIPTION
Pin Number
1 2 3 4 5, 6, 7, 8
Name
5 VSB 5 VIN 3.3 VOUT 3.3 VAUX GND
Function
Secondary power input for the Regulator Primary power input for the Regulator Output 3.3 V Power input for the bypass function Grounds
Document Number: 71340 S-40704--Rev. B, 19-Apr-04
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SI91860
Vishay Siliconix
ORDERING INFORMATION
Part Number
SI91860DY-T1 SI91860DY-T1--E3 SI91860DY -40 to 85_C
Temperature Range
Package
Tape and Reel Bulk
Eval Kit
SI91860DB
Temperature Range
-40 to 85_C
Board Type
Surface Mount
TYPICAL CHARACTERISTICS
1.0
Ground Current vs Temperature (5 VIN or 5 VSB)
IOUT = 600 mA
1.0
Ground Current vs Input Voltage (5 VIN or 5 VSB)
IOUT = 0
0.8 Ground Current (mA) Ground Current (mA) IOUT = 400 mA 0.6 IOUT = 200 mA
0.8
3.3 VAUX = 0 V
0.6
0.4
IOUT = 0 mA
0.4
0.2 5 VIN or 5 VSB = 5 V 0.0 -40
0.2
0.0 -20 0 20 40 (oC) 60 80 100 0 1 2 3 Input Voltage (V) 4 5 6 Temperature
0.35
ON-Resistance vs 3.3 VAUX Input Voltage
0.8
Ground Current vs 3.3 VAUX Input Voltage
0.30 Ground Current (mA)
0.6
Resistance ()
0.25
85_C 25_C -40_C
0.4
5 VIN = 5 V
0.20
0.15
0.2
5 VIN = 5 VSB =0 V
0.10 3.0
3.1
3.2
3.3
3.4
3.5
3.6
0.0 0.0
0.6
1.2
1.8
2.4
3.0
3.6
3.3 VAUX Input Voltage (V)
3.3 VAUX Input Voltage (V)
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Document Number: 71340 S-40704--Rev. B, 19-Apr-04
SI91860
Vishay Siliconix
TYPICAL WAVEFORMS
Load Transient Response-1
Load Transient Response-2
VOUT = 10 mV/div
VOUT = 10 mV/div
IOUT = 100 mA/div IOUT = 100 mA/div
Input = 5 VIN or 5 VSB IOUT = 1 to 150 mA trise = 2 msec
M 5.00 ms
Input = 5 VIN or 5 VSB IOUT = 150 to 1 mA tFALL= 2 msec
M 5.00 ms
Load Transient Response-3
Load Transient Response-4
VOUT = 50 mV/div
VOUT = 50 mV/div
IOUT = 200 mA/div
IOUT = 200 mA/div
Input = 5 VIN or 5 VSB IOUT = 0 to 400 mA trise = 2 msec
M 5.00 ms
Input = 5 VIN or 5 VSB IOUT = 400 to 0 mA tFALL = 2 msec
M 5.00 ms
5 VIN Power Up (5 VSB = 5 V)
5 VSB 200 mV/div (offset = 5 V)
5 VIN Power Down (5 VSB = 5 V)
3.3 VOUT (100 mV/div)
5 VSB 200 mV/div (offset = 5 V) 3.3 VOUT (100 mV/div)
5 VIN 500 mV/div (offset = 4.3 V)
5 VIN 500 mV/div (offset = 4.2 V)
5 VSB = 5 V 3.3 VAUX = 0 V IOUT = 400 mA
M 5.00 ms
5 VSB = 5 V 3.3 VAUX = 0 V IOUT = 400 mA
M 5.00 ms
Document Number: 71340 S-40704--Rev. B, 19-Apr-04
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SI91860
Vishay Siliconix
TYPICAL WAVEFORMS
5 VIN Power Down (3.3 VAUX = 3.3 V)
3.3 VAUX 200 mV/div (offset = 3.3 V) 3.3 VOUT (100 mV/div) 3.3 VOUT (100 mV/div) 3.3 VAUX 200 mV/div (offset = 3.3 V)
5 VIN Power Up (3.3 VAUX = 3.3 V)
5 VIN 500 mV/div (offset = 4.2 V)
5 VIN 500 mV/div (offset = 4.3 V)
5 VSB = 0 V 3.3 VAUX = 3.3 V IOUT = 400 mA
M 5.00 ms
5 VSB = 0 V 3.3 VAUX = 3.3 V IOUT = 400 mA
M 5.00 ms
Line Transient -1 (5 VIN and 5 VSB)
5 VIN (1 V/div)
Line Transient -2 (5 VIN and 5 VSB)
5 VIN (2 V/div)
3.3 VOUT (10 mV/div)
3.3 VOUT (10 mV/div)
5 VIN = 4.5 to 5.5 V IOUT = 150 mA TRISE = 5 sec
M 5.00 ms
5 VIN = 5.5 to 4.5 V IOUT = 150 mA TTALL = 5 sec
M 5.00 ms
Power Supply Ripple Rejection vs. Frequency
0 -10 -20 -30 -40 -50 PSRR(dB) -60 -70 -80 1 10 100 1K Frequency (Hz) www.vishay.com Document Number: 71340 S-40704--Rev. B, 19-Apr-04 10 K 100 K 1M PSRR 5 VIN = 5.0 V) ILOAD = 150 mA
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SI91860
Vishay Siliconix
BLOCK DIAGRAMS AND TYPICAL APPLICATION CIRCUIT
SI91860
1 5 VSB 4.7 F
5 VSB Regulator Driver 2 4.7 F 3
5 VIN
3.3 VOUT 2.2 F
5 VIN Regulator Driver 4 3.3 VAUX 4.7 F
Logic Control
5, 6
7, 8
DETAIL DESCRIPTION
During normal operation, the 5-VIN input powers the fixed 3.3-V output (3.3 VOUT) through an internal linear regulator. When 5 VIN falls below 4.07 V, the 3.3-V output is powered through the linear regulator from 5 VSB. If both 5 VIN and 5 VSB are below 4.07 V, then the output (3.3 VOUT) is powered from 3.3-VAUX input. The power drawn sequence is from 5 VIN, then 5 VSB and lastly 3.3 VAUX. If both 5 VIN and 5 VSB are above 4.30 V, then 5 VIN will power the output. The device prevents reverse current from flowing from the output to any unbiased or low voltage input. Linear Regulator Mode The output is regulated at 3.3 V when either one of the 5-VIN or 5-VSB pins is more than 4.30 V. The 5 VIN takes precedence when both the 5-VIN and 5-VSB pins are more than valid threshold voltage (i.e. > 4.30 V). The linear regulator will regulate the output until both the 5-VIN and 5-VSB pins fall below 4.07 V.
Document Number: 71340 S-40704--Rev. B, 19-Apr-04
Bypass Mode When both the 5-VIN and 5-VSB pins fall below 4.07 V, the output is powered by 3.3 VAUX through a 0.2-W internal switch. Thermal and Over-current Protection Thermal protection limits total power dissipation in the device. It safeguards the device in the event of fault conditions. When the junction temperature exceeds 165_C, the device turns off. The device turns back on once its junction temperature cools down by approximately 20_C. The device has overcurrent protection (typically at 900 mA) when it operates in linear regulator mode. A continuous short at output pin (3.3 VOUT) will result in a pulsed output as the thermal protection circuitry cycles the device on and off. For continuous operation, do not exceed the junction rating of 150_C. In bypass mode, the device is not current limited.
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Legal Disclaimer Notice
Vishay
Notice
Specifications of the products displayed herein are subject to change without notice. Vishay Intertechnology, Inc., or anyone on its behalf, assumes no responsibility or liability for any errors or inaccuracies. Information contained herein is intended to provide a product description only. No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this document. Except as provided in Vishay's terms and conditions of sale for such products, Vishay assumes no liability whatsoever, and disclaims any express or implied warranty, relating to sale and/or use of Vishay products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright, or other intellectual property right. The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications. Customers using or selling these products for use in such applications do so at their own risk and agree to fully indemnify Vishay for any damages resulting from such improper use or sale.
Document Number: 91000 Revision: 08-Apr-05
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