MIC5271YM5 [MICROCHIP]
1.2 V-14V ADJUSTABLE NEGATIVE LDO REGULATOR, 0.9V DROPOUT, PDSO5;
| 型号： | MIC5271YM5 |
| 厂家： | 
MICROCHIP |
| 描述： | 1.2 V-14V ADJUSTABLE NEGATIVE LDO REGULATOR, 0.9V DROPOUT, PDSO5 光电二极管 输出元件 调节器 |
| 文件： | 总12页 (文件大小：1006K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
MIC5271
µCap Negative Low-Dropout Regulator
General Description
Features
The MIC5271 is a µCap 100mA negative regulator in a
SOT-23-5 package. With better than 2% initial accuracy,
this regulator provides a very accurate supply voltage for
applications that require a negative rail. The MIC5271
sinks 100mA of output current at very low dropout voltage
(600mV maximum at 100mA of output current).
Stable with ceramic or tantalum capacitor
Positive and negative enable thresholds
Low dropout voltage: 500mV @ 100mA
Low ground current: 25µA @ load = 100µA
Tight initial accuracy: ±2%
Tight load and line regulation
The µCap regulator design is optimized to work with low-
value, low-cost ceramic capacitors. The output typically
requires only a 1µF capacitance for stability.
Thermal shutdown and current-limit protection
IttyBitty 5-pin SOT-23 packaging
Zero-current off mode
Designed for applications where small packaging and
efficiency are critical, the MIC5271 combines LDO design
expertise with IttyBitty® packaging to improve performance
and reduce power dissipation. Ground current is optimized
to help improve battery life in portable applications. The
MIC5271 also includes a TTL-compatible enable pin,
allowing the user to put the part into a zero-current off
mode.
Applications
GaAsFET bias
Portable cameras and video recorders
PDAs
Battery-powered equipment
Post-regulation of DC-to-DC converters
The MIC5271 is available in the 5-pin SOT-23 package for
space saving applications and it is available with an
adjustable output.
Datasheets and support documentation are available on
Micrel’s web site at: www.micrel.com.
Typical Application
Regulator with Adjustable Negative Voltage Output
IttyBitty is a registered trademark of Micrel, Inc.
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
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Micrel, Inc.
MIC5271
Ordering Information
Part Number(1)
Marking(2)
Voltage
Adjustable
–3.0V
Junction Temperature Range
–40°C to +125°C
Package
SOT-23-5
SOT-23-5
SOT-23-5
MIC5271YM5
L9AA
MIC5271-3.0YM5
MIC5271-5.0YM5
L930
–40°C to +125°C
L950
–5.0V
–40°C to +125°C
Note:
1. Other voltages are available. Contact Micrel for details.
2. Underbar (_) symbol may not be to scale.
Pin Configurations
MIC5271YM5
Adjustable Output Voltage
(Top View)
MIC5271-3.0YM5
Fixed Output Voltage
(Top View)
MIC5271-5.0YM5
Fixed Output Voltage
(Top View)
Pin Description
MIC5271YM5
Pin Name
MIC5271-3.0YM5
Pin Name
MIC5271-5.0YM5
Pin Function
Pin Name
Pin Number
Enable Input. TTL logic-compatible enable input. Logic
HIGH = ON, Logic LOW or open = OFF.
1
2
EN
GND
ADJ
EN
GND
−
EN
GND
−
Ground
Adjustable (Input): Adjustable feedback output
connects to resistor voltage divider.
3
NC
−OUT
−IN
NC
−OUT
−IN
No Connect. Leave unconnected.
Negative Regulator Output.
Negative Supply Input.
−
4
5
−OUT
−IN
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MIC5271
Absolute Maximum Ratings(3)
Operating Ratings(4)
Input Voltage (V-IN)........................................ –16V to –3.3V
Enable Voltage (VEN)...................................... −16V to +16V
Junction Temperature (TJ) ........................–40°C to +125°C
Thermal Resistance (θJA)(5) ....................................235°C/W
Input Voltage (V-IN) ........................................ −20V to +0.3V
Enable Voltage (VEN)...................................... −20V to +20V
Power Dissipation (PD)..............................Internally Limited
Junction Temperature (TJ) ........................–40°C to +125°C
Lead Temperature (soldering, 10s)............................ 260°C
Storage Temperature (TS).........................–65°C to +150°C
ESD Rating.................................................................Note 6
Electrical Characteristics(7)
V-IN = V-OUT – 1.0V; COUT = 4.7µF, IOUT = 100µA; TJ = +25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless otherwise noted.
Symbol
Parameter
Condition
Min.
−2
Typ.
Max.
+2
Units
V-OUT
Output Voltage Accuracy
Output Voltage Temperature Coefficient
Line Regulation
Variation from nominal V-OUT
Note 8
%
+3
−3
100
∆V-OUT/∆T
∆V-OUT/V-OUT
ppm/°C
0.15
0.2
V-IN = V-OUT – 1V to –16V
0.04
%/V
1.8
IOUT = −100µA to −100mA,
Note 9
Load Regulation
0.4
%
∆V-OUT/V-OUT
2.0
-55
I
OUT = −100µA
-360
IOUT = −50mA
−500
−700
−900
−100
Dropout Voltage, Note 10
mV
V-IN − V-OUT
-500
IOUT = −100mA
-25
-0.9
-2.0
0.1
µA
I
OUT = −100µA
IGND
Ground Current, Note 11
IOUT = −50mA
IOUT = −100mA
VEN = ±0.6V
f = 120Hz
mA
-3.0
+1.0
IGND_SD
Ground Current in Shutdown
Ripple Rejection
−1.0
µA
dB
PSRR
ILIMIT
50
350
Current Limit
V-OUT = 0V
235
mA
Notes:
3. Exceeding the absolute maximum ratings may damage the device.
4. The device is not guaranteed to function outside its operating ratings.
5. The maximum allowable power dissipation is a function of the maximum junction temperature, TJ(max) the junction-to-ambient thermal resistance, θJA,
and the ambient temperature, TA. The maximum allowable power dissipation at any ambient temperature is calculated using: PD(max) = (TJ(max) – TA)
÷ θJA, where θJA is 235°C/W. Exceeding the maximum allowable power dissipation will result in excessive die temperature, and the regulator will go
into thermal shutdown. See the “Thermal Considerations” sub-section in the Application Information for details.
6. Devices are ESD sensitive. Handling precautions are recommended.
7. Specification for packaged product only.
8. Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
9. Regulation is measured at constant junction temperature using low duty cycle pulse testing. Parts are tested for load regulation in the load range
from 100µA to 100mA. Changes in output voltage due to heating effects are covered by the thermal regulation specification.
10. Dropout voltage is defined as the input to output differential at which the output voltage drops 2% below its nominal value measured at 1V
differential.
11. Ground pin current is the regulator quiescent current plus pass transistor base current. The total current drawn from the supply is the sum of the load
current plus the ground pin current.
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MIC5271
Electrical Characteristics(7) (Continued)
V-IN = V-OUT – 1.0V; COUT = 4.7µF, IOUT = 100µA; TJ = +25°C, bold values indicate –40°C ≤ TJ ≤ +125°C; unless otherwise noted.
Symbol
Parameter
Condition
Min.
Typ.
Max.
Units
TON
Turn-On Time
Input Low Voltage
Input high Voltage
Time to VOUT = 90% (nominal)
Regulator OFF
60
µs
±0.6
VEN
V
Regulator ON
±2.0
0.1
VEN = ± 0.6V and –2.0V
VEN = +2.0V
IEN
Enable Input Current
µA
10.0
5.6
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MIC5271
Typical Characteristics
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MIC5271
Typical Characteristics (Continued)
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Micrel, Inc.
MIC5271
Functional Characteristics
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MIC5271
Functional Diagrams
Figure 1. MIC5271YM5 (Adjustable Voltage)
Figure 2. MIC5271-xxYM5 (Fixed Voltage)
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MIC5271
Application Information
The MIC5271 is a general-purpose negative voltage
regulator that can be used in a system that requires a
clean negative voltage. This includes the post regulation
of DC-to-DC converters (transformer or charge pump
based voltage converters). These negative voltages
typically require a negative low dropout voltage regulator
to provide a clean output from noisy input power.
Input Capacitor
A 1µF input capacitor should be placed from −IN to GND
if there is more than two inches of wire or trace between
the input and the AC filter capacitor or if a battery is used
as the input.
Figure 3. Positive and Negative Enable Voltage vs. Supply
Voltage
Output Capacitor
The MIC5271 requires an output capacitor for stable
operation. A minimum of 1µF of output capacitance is
required. The output capacitor can be increased without
limitation to improve transient response. The output does
not require ESR to maintain stability; therefore a ceramic
capacitor can be used. High-ESR capacitors may cause
instability. Capacitors with an ESR of 3Ω or greater at
100kHz can cause a high-frequency oscillation.
Thermal Considerations
Absolute values will be used for thermal calculations to
clarify the meaning of power dissipation and voltage
drops across the part.
Proper thermal design for the MIC5271-5.0YM5 can be
accomplished with some basic design criteria and some
simple equations. The following information must be
known to implement your regulator design:
Low-ESR tantalums are recommended due to the tight
capacitance tolerance over temperature. The Z5U
dielectric can change capacitance value by as much 50%
over temperature, and the Y5V dielectric can change
capacitance value by as much as 60% over temperature.
To use a ceramic chip capacitor with the Y5V dielectric,
the value must be much higher than a tantalum to ensure
the same minimum capacitor value over temperature.
• VIN = Input voltage
• VOUT = Output voltage
• IOUT = Output current
• TA = Ambient operating temperature
• IGND = Ground current
No-Load Stability
The MIC5271 does not require a load for stability.
Maximum power dissipation can be determined by
knowing the ambient temperature (TA), the maximum
junction temperature (+125°C), and the thermal
resistance (junction-to-ambient). The thermal resistance
for this part, assuming a minimum footprint board layout,
is +235°C/W. The maximum power dissipation at an
ambient temperature of +25°C can be determined with
Equations 1 and 2:
Enable Input
The MIC5271 comes with an enable pin that allows the
regulator to be disabled. Forcing the enable pin higher
than the negative threshold and lower than the positive
threshold disables the regulator and sends it into a “zero”
off-mode current state. In this state, current consumed by
the regulator goes nearly to zero. The MIC5271 will be in
the “on” mode when the voltage applied to the enable pin
is either greater than the positive threshold or less than
the negative threshold.
TJ(MAX) − TA
PD(MAX)
=
=
Eq. 1
Eq. 2
θJA
125°C − 25°C
235°C/ W
P
D(MAX)
Where PD(MAX) = +425mW.
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Micrel, Inc.
MIC5271
The actual power dissipation of the regulator circuit can
be determined using Equation 3:
Adjustable Regulator Application
The MIC5271YM5 can be adjusted from −1.20V to −14V
by using two external resistors (Figure 4). The resistors
set the output voltage based on Equation 4.
PD = (VIN – VOUT) × IOUT + (VIN × IGND
)
Eq. 3
Substituting PD(MAX), determined above, for PD and solving
for the operating conditions that are critical to the
application will give the maximum operating conditions for
the regulator circuit. The maximum power dissipation
number cannot be exceeded for proper operation of the
device. The maximum input voltage can be determined
using the output voltage of 5.0V and an output current of
100mA. Ground current, of 2mA for 100mA of output
current, can be taken from the Electrical Characteristics.
• 425mW = (VIN − 5.0V)100mA + VIN × 2mA
• 425mW = (100mA × VIN + 2mA × VIN) −500mW
• 925mW = 102mA × VIN
Figure 4. Adjustable Voltage Application
• VIN = 9.07V (maximum)
Therefore, a –5.0V application at -100mA of output
current can accept a maximum input voltage of –9.07V in
a SOT-23 package. For a full discussion of heat sinking
and thermal effects on voltage regulators, refer to
“Regulator Thermals” section of Micrel’s Designing with
Low Dropout Voltage Regulators handbook.
R2
R1
V
=V
1+
Eq. 4
OUT
REF
Where VREF = 1.20V.
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Micrel, Inc.
MIC5271
Package Information and Recommended Landing Pattern(12)
5-Pin SOT-23 (M5)
Note:
12. Package information is correct as of the publication date. For updates and most current information, go to www.micrel.com.
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Micrel, Inc.
MIC5271
MICREL, INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
TEL +1 (408) 944-0800 FAX +1 (408) 474-1000 WEB http://www.micrel.com
Micrel, Inc. is a leading global manufacturer of IC solutions for the worldwide high performance linear and power, LAN, and timing & communications
markets. The Company’s products include advanced mixed-signal, analog & power semiconductors; high-performance communication, clock
management, MEMs-based clock oscillators & crystal-less clock generators, Ethernet switches, and physical layer transceiver ICs. Company
customers include leading manufacturers of enterprise, consumer, industrial, mobile, telecommunications, automotive, and computer products.
Corporation headquarters and state-of-the-art wafer fabrication facilities are located in San Jose, CA, with regional sales and support offices and
advanced technology design centers situated throughout the Americas, Europe, and Asia. Additionally, the Company maintains an extensive network
of distributors and reps worldwide.
Micrel makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this datasheet. This
information is not intended as a warranty and Micrel does not assume responsibility for its use. Micrel reserves the right to change circuitry,
specifications and descriptions at any time without notice. No license, whether express, implied, arising by estoppel or otherwise, to any intellectual
property rights is granted by this document. Except as provided in Micrel’s terms and conditions of sale for such products, Micrel assumes no liability
whatsoever, and Micrel disclaims any express or implied warranty relating to the sale and/or use of Micrel products including liability or warranties
relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright, or other intellectual property right.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product
can reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical
implant into the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a significant injury to the user. A
Purchaser’s use or sale of Micrel Products for use in life support appliances, devices or systems is a Purchaser’s own risk and Purchaser agrees to fully
indemnify Micrel for any damages resulting from such use or sale.
© 2003 Micrel, Incorporated.
April 6, 2015
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相关型号：
MIC5271YM5TR
1.2 V-14V ADJUSTABLE NEGATIVE LDO REGULATOR, 0.9V DROPOUT, PDSO5, SOT-23, 5 PIN
MICROCHIP
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