SC4437SK-3.3TRT [SEMTECH]
Wide Input Voltage Range Precision Voltage Reference; 宽输入电压范围精密基准电压源
| 型号： | SC4437SK-3.3TRT |
| 厂家： | 
SEMTECH CORPORATION |
| 描述： | Wide Input Voltage Range Precision Voltage Reference |
| 文件： | 总12页 (文件大小：395K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
SC4437
Wide Input Voltage Range
Precision Voltage Reference
POWER MANAGEMENT
Features
Description
The SC4437 is a low power precision series bandgap
reference device. It accepts wide input voltage range VOUT
+ 0.9V to 28V and generates stable output voltage with
superior accuracy and low drift over operating
temperatures. The SC4437 is ideal for battery powered
systems where there can be wide variations in supply
voltage and a need to minimize power dissipation.
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VIN Voltage Range: VOUT + 0.9V to 28V
VOUT: Fixed 3.3V
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VOUT High Accuracy ( 1ꢀ ꢁ over -40°C to 125°C
VOUT Low Temperature Coe#cient
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Output Current up to 20mA
Low (< 160µAꢁ Quiescent Current
Stable without Compensation Capacitor
Available with Compact, Surface Mount SOT-23
Package
The SC4437 is able to supply up to 20mA output current
with excellent line and load regulation characteristics.
The output compensation capacitor is optional. It
provides user the &exibility of compact, low cost design
or further noise performance enhanced design.
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Pb-Free, Halogen Free, RoHS/WEEE compliant
product
Applications
The SC4437 is available in a compact 3-lead surface
mount SOT-23 package.
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Bias Supplies
High Accuracy Micropower Supplies
Data Acquisition Systems
Medical Devices
Portable Battery Powered Equipment
Test Equipment
Automotive and Industrial
Typical Application Circuit
SC4437
GND
V
IN up to 28V
OUT
3.3V
CO
IN
CIN
0.1 µF
(optional)
September 21, 2009
www.semtech.com
1
SC4437
Pin Con!guration
Ordering Information
Device
Package
SC4437SK-3.3TRT
SC4437EVB
3-Lead Plastic SOT-23
Evaluation Board
TOP VIEW
IN 1
Notes:
(1ꢁ Available in tape and reel only. A reel contains 3,000 devices.
(2ꢁ Pb-Free, Halogen Free, RoHS/WEEE compliant product.
3 GND
OUT 2
3-LEAD PLASTIC SOT-23
= 202°C/W
θ
JA
Marking Information
© 2009 Semtech Corp.
www.semtech.com
2
SC4437
Recommended Operating Conditions
Absolute Maximum Ratings
VIN Voltage …………………… …………………… 4.2 to 28V
Maximum Output Current ………………………………… 20mA
Temperature Range ……………………………-40=C to 125=C
VIN Voltage ……………………………………………… 30V
Reverse Voltage …………………………………………-15V
Output Short Circuit Duration ………………… Indefinite(1ꢁ
Lead Temperature (Solderingꢁ 10 seconds (2ꢁ ………… 260°C
ESD Rating ……………………………………… … …… 2kV
Thermal Information
Thermal Resistance, Junction to Ambient(3ꢁ ……… 202 °C/W
Maximum Junction Temperature …………………… +150°C
Storage Temperature Range(4ꢁ ………………-65°C to +150°C
Exceeding the above speci*cations may result in permanent damage to the device or device malfunction. Operation outside of the parameters
speci*ed in the Electrical Characteristics section is not recommended.
NOTES:
(1) For VIN ≤ 10 V.
(2) Compatible for Wave Soldering and IR Re&ow.
(3) Calculated from package in still air, mounted to 3”x 4.5”, 4 layer FR4 PCB per JESD51 standards.
(4) If the part is stored outside of the speci*ed temperature range, the output may drift.
Electrical Characteristics
Unless speci*ed: VINꢂ VOUT + 2.5V, IOUT ꢂ 0, CINꢂ 0.1µF, CO ꢂ 0µF, -40°C< TA ꢂTJ < 125°C
Parameter
Symbol
Conditions
Min
Typ
Max
Units
INPUT
Input Voltage Range
VIN
Refer to Line Regulation Spec.
IOUT ꢂ 0
4.2
28
V
V
V
V
0.6
0.9
0.9
Drop Out Voltage
VIN-VOUT
IOUT ꢂ 10mA, TA ꢂ 25°C
IOUT ꢂ 10mA
1.28
1.38
Leakage Current for Input Voltage
Reverse Connection
ꢀΑ
IREV
VIN ꢂ -15V
TA ꢂ 25°C
2
6
ꢀΑ
ꢀΑ
110
180
220
Quiescent Current
IQ
OUTPUT
Output Voltage
VOUT
ꢀ
TJ ꢂ25°C
3.3
V
0°C≤TJ < 100°C, 0mA<IOUT ≤ 20mA,
4.2V ≤VIN ≤28V
Output Voltage Accuracy
Line Regulation
-1
1
ꢀ
TA ꢂ 25°C
100
50
500
3300
100
ppm/V
ppm/V
ppm/V
ppm/V
VOUT + 0.9V ≤ VIN ≤ VOUT +2.5V
VOUT + 2.5V ≤ VIN ≤ 28V
dVOUT/dVIN
TA ꢂ 25°C
300
© 2009 Semtech Corp.
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3
SC4437
Electrical Characteristics (continued)
Unless speci*ed: VINꢂ VOUT + 2.5V, IOUT ꢂ 0, CINꢂ 0.1µF, CO ꢂ 0µF, -40°C< TA ꢂTJ < 125°C
Parameter
Symbol
Conditions
Min
Typ
Max
Units
TA ꢂ 25°C
TA ꢂ 25°C
TA ꢂ 25°C
3000
4000
6000
150
ppm/mA
ppm/mA
ppm/mA
ppm/mA
ppm/mA
ppm/mA
IOUT ꢂ 100µA
100
75
Load Regulation
dVOUT/dILOAD
IOUT ꢂ 10mA
IOUT ꢂ 20mA
250
100
150
Output Voltage Temperature
Coe# cient
dVOUT/dT
ISC
0°C≤ TJ < 105°C
80
55
120
ppm/°C
mA
Output Short Circuit Current
Short VOUT to GND, TA ꢂ 25°C
DYNAMIC
VIN > VOUT + 2.5V, VOUT settles to 0.05ꢀ of *nal
value
3 (1ꢁ
Turn-On Settling Time
TON
ms
NOTES:
(1) Guaranteed by design.
© 2009 Semtech Corp.
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4
SC4437
Pin Descriptions
Pin #
Pin Name Pin Function
1
2
3
VIN
Input supply voltage for the precision voltage reference.
Output voltage.
VOUT
GND
Ground connection for the circuit.
© 2009 Semtech Corp.
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5
SC4437
Typical Waveforms
Minimum Input - Output Voltage Di@erential
Supply Current vs Input Voltage
Supply Current vs Input Voltage
Minimum Input-Output Voltage Differential
20
150
140
130
120
15
125 °C
125 °C
-55 °C
110
100
90
80
70
60
50
10
5
25 °C
-55 °C
25 °C
0
0
0.5
1
1.5
2
0
5
10
15
20
Input-Output Voltage (V)
Input Voltage (V)
Load Regulation - Sourcing
Load Regulation - Sinking
Load Regulation, Sourcing
Load Regulation, Sinking
10
0
180
130
80
25 °C
-10
-20
-30
125 °C
125 °C
30
25 °C -55 °C
-55 °C
-20
0
5
10
15
20
0
0.2 0.4 0.6 0.8
1
1.2 1.4 1.6 1.8
2
Output Current (mA)
Output Current (mA)
Line Regulation
Power Supply Rejection Ratio vs Frequency
Line Regulation
Power Supply Rejection Ratio vs Frequency
3.31
3.3
100
25 °C
3.29
3.28
3.27
3.26
125 °C
-55 °C
10
1
0.1
1
10
100
1000
0
5
10
Input Voltage (V)
15
20
Frequency (KHz)
© 2009 Semtech Corp.
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6
SC4437
Typical Waveforms (Continued)
Output Impedance
Start Up with Input Voltage 20 V
Output Impedance vs Frequency
1000
100
No Output Cap
10
1
)F Output Cap
1
0.01
0.1
1
10
100 1000
Frequency (KHz)
Output Noise Waveform 0.1Hz to 10 Hz
Output Noise Performance 10 Hz to 100 kHz
Noise Density VS Frequency
1.000
0.100
0.01
0.1
1
10
100
Frequency (kHz)
1 mA Transient Response with 1 µF Output Cap
1 mA Transient Response without Output Cap
© 2009 Semtech Corp.
www.semtech.com
7
SC4437
Block Diagram
VIN
VOUT
GND
© 2009 Semtech Corp.
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8
SC4437
Applications Information
Advantage Over Shunt References
improve the dynamic response under load transient. In
order to obtain optimum performance under load
transient, it is recommended that a 0.1 ꢀF ceramic
capacitor placed at the input and a 1 ꢀF (and upꢁ ceramic
capacitor placed at the output.
The SC4437 is a low power precision series voltage
reference. The series reference has major advantages over
shunt references when the load current has variations and
the reference is powered by a battery. A shunt reference
requires a resistance to connect the input and the output.
This resistance will be designed to consume the maximum
load current. When the actual load current is smaller than
the maximum load current, the difference will be
consumed by the reference. This behavior not only reduce
efficiency but also increase the thermal stress on the
device, thus is not desirable. On the contrary, the series
reference consumes the same current as the load. When
there is no load current required, the device itself
consumes very little current (in the scale of 10s of ꢀAꢁ.
Reverse Battery Connection Protection
The SC4437 has reverse battery connection protection.
When the input and ground is reversely connected, the
leakage current from the input is very small (maximum 6
ꢀAꢁ, protecting both the battery and the device itself.
Load Transient Responses
The following * g ure shows the circuit setup to test the 1
mA load transient response.
3.3V
Precision Reference Over Wide Input Voltage Range, Load
Conditions and Operating Temperatures
2.3V
SC4437
GND
1 kꢀ
5.8V
The SC4437 can maintain 1ꢀ precision regulation over
wide load range, operating temperature condition and
input voltage range. To provide 3.3V output voltage, the
load can range from 0 to 20mA; the temperature can
range from -40 °C to 125 °C; the input voltage can range
from VOUT + 0.9V to 28V, depending on the load and
temperature conditions. The input voltage range should
be selected based on the drop out voltage speci*cation.
Although the SC4437 can maintain tight regulation over
wide operating conditions, attention should be paid to
the thermal stress of the device. For example, with the
input voltage of 28V and the load current of 20mA, the
power consumption on the device is
OUT
3.3V
IN
CO
CIN
0.1 µF
(optional)
Without output capacitance, the transient response is
shown below.
P ꢂ (28V-3.3Vꢁꢃ0.02A ꢂ 0.494W
With the thermal resistance of 202 °C/W, the power
consumption on the chip gives an ambient to junction
temperature increase of 99.8 °C. If the ambient temperature
is higher than 25 °C, then the junction temperature will be
higher than 125°C, thus should be avoided.
The high overshoot is due to the high resistance at high
frequency without output capacitance.
Input and Output Capacitances
With 1ꢀF capacitance, the transient response is improved
signi*cantly. The *gure below shows the 1mA transient
response with 1 ꢀF capacitance at the output.
The SC4437 is stable with or without output capacitors
under all load conditions. Adding output capacitances can
© 2009 Semtech Corp.
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9
SC4437
Applications Information (continued)
Noise Density VS Frequency
1.000
0.100
0.01
0.1
1
10
100
Frequency (kHz)
Start Up
With the input voltage 5.8V, the device shows very small
start up overshoot, as shown by the *gure below.
Low Noise Operation
The SC4437 is a low noise reference.The noise is measured
with high gain ampli*cation and band *ltering. Without
any output capacitor the noise level is measured to be
around0.7ꢀV/√Hzfrom0to100kHz.Withoutputcapacitor
the noise level will be signi*cantly lower. The following
* g ure shows the noise measurement result under room
temperature without output capacitor from 10Hz to
100kHz and the scope picture of noise measurement
result from 0.1 Hz to 10 Hz .
© 2009 Semtech Corp.
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10
SC4437
Outline Drawing – SOT-23 3L
D
A
DIMENSIONS
INCHES MILLIMETERS
DIM
A
e1
MIN NOM MAX MIN NOM MAX
-
-
-
.035
.044 0.89
.004 0.01
1.12
0.10
3
-
A1 .000
B
A2 .035 .037 .040 0.88 0.95 1.02
-
-
-
-
b
.012
.003
.020 0.30
.007 0.08
0.51
0.18
c
D
E
.110 .114 .120 2.80 2.90 3.04
.082 .093 .104 2.10 2.37 2.64
E
E1
E1 .047 .051 .055 1.20 1.30 1.40
e
.075
.037
1.90 BSC
0.95 BSC
e1
L
.015 .020 .024 0.40 0.50 0.60
L1
N
.022
(0.55)
3
3
-
-
1
2
0
0°
8°
0°
8°
aaa
.004
.008
0.10
0.20
bbb
bxN
bbb
C A B
e
A2
A
aaa
C
3X
SEATING PLANE
H
A1
C
c
GAUGE
PLANE
0
SEATING
PLANE
0.25
C
L
SEE DETAIL A
L1
SIDE VIEW
DETAIL A
NOTES:
1. CONTROLLING DIMENSIONS ARE IN MILLIMETERS (ANGLES IN DEGREES).
-A-
-H-
2.
3.
-B-
TO BE DETERMINED AT DATUM PLANE
DATUMS
AND
DIMENSIONS "E1" AND "D" DO NOT INCLUDE MOLD FLASH, PROTRUSIONS
OR GATE BURRS.
© 2009 Semtech Corp.
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11
SC4437
Land Pattern – SOT-23
Contact Information
Semtech Corporation
Power Management Products Division
200 Flynn Road, Camarillo, CA 93012
Phone: (805ꢁ 498-2111 Fax: (805ꢁ 498-3804
www.semtech.com
12
© 2009 Semtech Corp.
www.semtech.com
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