SI4779CY-T1 [VISHAY]
Power Management Circuit, PDSO8;
| 型号： | SI4779CY-T1 |
| 厂家： | 
VISHAY |
| 描述： | Power Management Circuit, PDSO8 光电二极管 |
| 文件： | 总9页 (文件大小：120K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Si4779CY
Vishay Siliconix
High-Side N-Channel Switch with Current Limit
FEATURES
APPLICATIONS
•
•
•
•
User Set Over Current Limit From 400 mA to 2.4 A
Low r ) 45 mΩ (max) at 25 °C
Fault Indicator
•
•
•
•
•
Notebook Computers Power Management
USB Power Distribution
Hot Plug In Power Supplies
Power Supply/Load Protection
Battery-Charger Circuits
Pb-free
DS(on
Available
Under Voltage Lockout
RoHS*
COMPLIANT
DESCRIPTION
The Si4779CY n-channel high-side switch combines a
MOSFET junction temperature within specification,
thereby eliminating the need for thermal shutdown.
The low quiescent current makes the Si4779CY ideal
for use in battery powered devices. The Si4779CY
operates on both 3 V and 5 V busses, and is packaged
low r
MOSFET switch with a user set, pulse gate
DS(on)
control (PGC) based current limit. This switch is
designed to protect the system power supply from
overloads and short circuit conditions in applications
such as USB. The PGC based approach to the current
limiter provides the additional benefit of keeping the
®
in the LITTLE FOOT SO-8 package.
FUNCTIONAL BLOCK DIAGRAM
IN
OUT
–
FAULT
SET
Control
Circuit
V
R
ON
GND
See page 7 for a detailed block diagram.
FIGURE 1.
* Pb containing terminations are not RoHS compliant, exemptions may apply.
Document Number: 71664
S-60423–Rev. B, 20-Mar-06
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1
Si4779CY
Vishay Siliconix
ABSOLUTE MAXIMUM RATINGS T = 25 °C, unless otherwise noted
A
Parameter
Symbol
VIN
Limit
- 0.3 to 7
- 0.3 to 7
2.4
Unit
Voltage, IN to GND
Voltage, ON
V
VON
TA = 25 °C
TA = 85 °C
TA = 70 °C
Continuous Drain Current (TJ = 150 °C)a
ID
A
2.4
Maximum Power Dissipationa
PD
0.65
W
TJ, Tstg
Operating Junction and Storage Temperature Range
- 65 to 125
°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 CONDITIONS
Parameter
Symbol
VIN
Typical
3.0 to 5.0
0 to 5.0
0 to 85
Unit
V
Voltage, IN to GND
Voltage, ON or FAULT to GND
VON, VFAULT
TA
Operating Temperature Range
°C
THERMAL RESISTANCE RATINGS
Parameter
Junction-to-Ambienta
Junction-to-Foot (Drain)b
Symbol
RthJA
RthJF
Typical
98
Maximum
Unit
°C/W
120
46
Steady State
37
Notes:
a. Surface mounted on 1" x 1" FR4 board, 0.062" thick, 2-oz copper double sided.
b. Junction-to-foot thermal impedance represents the effective thermal impedance of all heat carrying leads in parallel and is intended for use
in conjunction with the thermal impedance of the PC board pads to ambient (RthJA = RthJF + RthPCB-A). It can also be used to estimate chip tem-
perature if power dissipation and the lead temperature of a heat carrying (drain) lead is known.
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Document Number: 71664
S-60423–Rev. B, 20-Mar-06
Si4779CY
Vishay Siliconix
SPECIFICATIONS
Test Conditions Unless Specified
A = 25 °C, VIN = 5 V
Limits
Typa
Parameter
Symbol
Unit
T
Min
Max
Basic Operations
VIN
Operating Voltage
2.7
5.5
0.045
0.055
2
V
VIN= 4.75 V, ID = 2 A
IN= 3.0 V, ID = 2 A
0.035
0.045
rDS(on)
On-State Resistance
Ω
V
ISUP(off)
ISUP(on)
VONL
ON = IN, VIN = 5.5 V, VOUT = 0 V
Supply Current
µA
ON = GND, VIN = VOUT = 5.5 V, IOUT = 0 V
70
V
V
IN = 2.7 V to 5.5 V
IN = 2.7 V to 3.6 V
ON Input Low Voltage
ON Input High Voltage
0.8
2.0
2.4
V
µA
A
VONH
ION
VIN = 4.5 V to 5.5 V
VON = 5.5 V
ON Input Current
0.01
1
Protection
Over Current Limit Rangeb
Under Voltage Lockout (rising edge)
Under Voltage Lockout (falling edge)
Under Voltage Hysteresis
FAULT Output Voltage Lowb
FAULT Logic Output Leakage Current
Dynamicb
Turn-On Time
Rise Time
ILIMIT
Tolerance = 20 ꢀ, VIN = 5 V
0.4
2.0
2.0
2.4
4.0
2.6
UVLOrise
UVLOfall
2.3
0.1
V
ΔUVLO
VFAULT
IFL
ISINK = 100 µA
0.4
1
VIN = VFAULT = 5.5 V
0.01
µA
ms
ton
tr
3
VIN = 5 V, RL = 11 Ω, CL = 40 µF
3.5
1.5
0.5
8
toff
tf
Turn-Off Time
Fall Time
VIN = 5 V, IOUT = 500 mA
µs
tcyc
VIN = 5 V, RL = 0.5 Ω
Cycle Time
ms
Notes:
a. Typical values at TA = 25 °C are for DESIGN AID ONLY, not guaranteed nor subject to production testing.
b. Guaranteed by design. Derived from ISET current ratio, current-limit amplifier and external set resistor accuracy.
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.
TIMING DIAGRAMS
50 %
50 %
ON
ON
ON
ON
90 %
90 %
OUT
50 %
OUT
50 %
10 %
10 %
OUT
OUT
ton
toff
trise
tfall
FIGURE 2.
FIGURE 3.
Document Number: 71664
S-60423–Rev. B, 20-Mar-06
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3
Si4779CY
Vishay Siliconix
TIMING DIAGRAMS
ON
V
RSET
I
LIMIT
tcyc
FIGURE 4.
TYPICAL CHARACTERISTICS 25 °C, unless noted
2.5
2.0
V
= 5 V
IN
1.5
1.0
0.5
0.0
R
SET
value is measured in circuit
200
300
400
500
600
700
800
900
1000
1100
1200
1300
1400
1500
1600
1700
1800
1900
R
SET
( )
FIGURE 5. RSET vs. ILIMIT
1.4
1000
100
V
= 5.5 V
IN
1.2
1.0
0.8
0.6
0.4
10
1
- 40
- 20
0
20
40
60
80
100
- 40 - 25 - 10
5
20
35
50
65
80
95
T – Ambient Temperature (°C)
A
T – Ambient Temperature (°C)
A
FIGURE 6. Supply Current, Output Disable vs.
Ambient Temperature Over Operating Voltage
FIGURE 7. Normalized On-Resistance
vs. Ambient Temperature
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Document Number: 71664
S-60423–Rev. B, 20-Mar-06
Si4779CY
Vishay Siliconix
TYPICAL WAVEFORMS V = 5 V, T = 25 °C, unless otherwise noted
IN
A
20 ms/div
1 ms/div
CH1: I
CH2: V
CH3: ON, 5 V/div
, 2 A/div
, 5 V/div, C = 47 µF
OUT
OUT
CH1: I
CH2: V
CH3: ON, 5 V/div
, 0.5 A/div
, 5 V/div, C = 10 µF
OUT L
OUT
L
FIGURE 9. Switch Turn-ON Time
FIGURE 8. Switch Turn-ON/OFF Time
200 µs/div
CH1: I
50 µs/div
CH1: I
, 0.5 A/div
, 5 V/div, C = 150 µF
OUT
OUT
, 0.5 A/div
, 5 V/div, C = 10 µF
OUT
OUT
CH2: V
CH3: ON, 5 V/div
L
CH2: V
CH3: ON, 5 V/div
L
NOTE: Discharge time based primarily on external R and C
NOTE: Discharge time based primarily on external R and C
FIGURE 11. Switch Turn-OFF Time
FIGURE 10. Switch Turn-OFF Time
Document Number: 71664
S-60423–Rev. B, 20-Mar-06
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5
Si4779CY
Vishay Siliconix
TYPICAL WAVEFORMS V = 5 V, T = 25 °C, unless otherwise noted
IN
A
2 ms/div
2 ms/div
CH1: ON, 5 V/div
CH2: V , 5 V/div, R = 0.5 Ω, C = 47 µF
CH1: ON, 5 V/div
OUT
L
L
CH2: V
CH3: V
, 500 mV/div
, 5 V/div, R = 5.6 Ω, C = 100 µF
, 1 A/div
RESET
OUT
CH3: FAULT, 5 V/div
CH4: I , 1 A/div
L
L
OUT
CH4: I
OUT
FIGURE 12. FAULT to Short Response (tcyc
)
FIGURE 13. VRESET to Over Current Response
2 ms/div
2 ms/div
CH1: ON, 5 V/div
CH2: PS Droops, 50 mV/div, Offset = 5 V
CH1: ON, 5 V/div
CH2: PS Droops, 100 mV/div, Offset = 5 V
CH3: V
, 1 V/div, R = 0.5 Ω, C = 100 µF
CH3: V
, 1 V/div, R = 0.5 Ω, C = 100 µF
OUT
, 0.5 A/div
L L
OUT
, 2 A/div
L L
CH4: I
CH4: I
OUT
OUT
NOTE: Special test with 820-µFcapacitor at PS and R
setup for 0.5 A.
NOTE: Special test with 820-µFcapacitor at PS and R
setup for 2.4 A.
SET
SET
FIGURE 15. Power Supply Droops vs. Short
FIGURE 14. Power Supply Droops vs. Short
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Document Number: 71664
S-60423–Rev. B, 20-Mar-06
Si4779CY
Vishay Siliconix
PIN CONFIGURATION
PIN DESCRIPTION
Pin Symbol
SO-8
Description
1, 2
3
IN
Input. N-channel MOSFET drain, bypass IN with a
100 µF capacitor to GND.
IN
IN
OUT
1
2
3
4
8
7
6
5
OUT
ON
Active-low switch-on input, logic low turns switch
on. ON needs to be connected to VIN during power
Si4779CY
ON
ET
FAULT
GND
up, then connect to GND to activate the switch
after power up.
4
SET
Current-limit input. A resistor from SET to GND
sets the current limit for the switch.
Top View
Ordering Information: Si4779CY-T1
Si4779CY-T1-E3 (Lead (Pb)-free)
5
6
GND
Ground
FAULT Fault indicator output. This open drain output goes
low when the circuit is in current limit or in short
circuit protection mode.
7, 8
OUT
Switch output. N-channel MOSFET source.
DETAILED BLOCK DIAGRAM
1
2
8
IN
IN
OUT
7
OUT
–
EA
UVLO
CP
BG
3
ON
QB
Q
R
S
6
+
–
FAULT
D
+
–
4
SET
5
GND
R
SET
FIGURE 16.
Document Number: 71664
S-60423–Rev. B, 20-Mar-06
www.vishay.com
7
Si4779CY
Vishay Siliconix
DETAILED DESCRIPTION
The SI4779CY limits the output current to a user-defined age power consumption, which is designed to be kept
level. When the output current passes through the main under 500 mW.
switch a fraction of this current passes through a replica
switch and R
.
If the output is shorted, the circuit will go into an on-off
cycle to protect the switch and to prevent the battery
SET
R
is an external sense resistor used to set the level from draining down.
SET
of the over current limit; the over current limit should be
set between 0.4 A and 2.4 A (see graph for R value The fault output (FAULT) goes low when the circuit is in
SET
vs. current limit). The circuit shuts down the switch when over current limit or short circuit protection mode. A 100 k
Ω
the current flowing through the switch exceeds Ilimit. pull-up resistor from FAULT to IN provides a logic-con-
After a short period of time, the circuit will slowly turn on trol signal.
the switch again. The length of time off is based on aver-
APPLICATIONS DIAGRAM
Line Input
Line Output
IN
OUT
100 kΩ
100 µF
100 kΩ
FAULT
100 µF
11 Ω
Si4779CY
ON
ON
SET
GND
R
SET
FIGURE 17.
Vishay Siliconix maintains worldwide manufacturing capability. Products may be manufactured at one of several qualified locations. Reliability data for Silicon Tech-
nology and Package Reliability represent a composite of all qualified locations. For related documents such as package/tape drawings, part marking, and reliability
data, see http://www.vishay.com/ppg?71664.
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Document Number: 71664
S-60423–Rev. B, 20-Mar-06
Legal Disclaimer Notice
Vishay
Disclaimer
All product specifications and data are subject to change without notice.
Vishay Intertechnology, Inc., its affiliates, agents, and employees, and all persons acting on its or their behalf
(collectively, “Vishay”), disclaim any and all liability for any errors, inaccuracies or incompleteness contained herein
or in any other disclosure relating to any product.
Vishay disclaims any and all liability arising out of the use or application of any product described herein or of any
information provided herein to the maximum extent permitted by law. The product specifications do not expand or
otherwise modify Vishay’s terms and conditions of purchase, including but not limited to the warranty expressed
therein, which apply to these products.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted by this
document or by any conduct of Vishay.
The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications unless
otherwise expressly indicated. Customers using or selling Vishay products not expressly indicated for use in such
applications do so entirely at their own risk and agree to fully indemnify Vishay for any damages arising or resulting
from such use or sale. Please contact authorized Vishay personnel to obtain written terms and conditions regarding
products designed for such applications.
Product names and markings noted herein may be trademarks of their respective owners.
Document Number: 91000
Revision: 18-Jul-08
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