MIC29302HWU

MIC29302HWU
High-Current Low-Dropout Regulators
General Description
The MIC29302HWU is a high current, high accuracy, lowdropout voltage regulators. Using Micrel's proprietary
Super βeta PNP® process with a PNP pass element, these
regulators feature 350mV to 425mV (full load) typical
dropout voltages and very low ground current. Designed
for high current loads, these devices also find applications
in lower current, extremely low dropout-critical systems,
where their tiny dropout voltage and ground current values
are important attributes.
The MIC29302HWU is fully protected against overcurrent
faults, reversed input polarity, reversed lead insertion,
over-temperature operation, and positive and negative
transient voltage spikes. Five pin fixed voltage versions
feature logic level ON/OFF control and an error flag which
signals whenever the output falls out of regulation.
Flagged states include low input voltage (dropout), output
current limit, over-temperature shutdown, and extremely
high voltage spikes on the input.
The ENABLE pin may be tied to VIN if it is not required for
ON/OFF control. The MIC29302HWU is available in a 5pin surface mount TO-263 (D2Pak) package.
For
applications with input voltage 6V or below, see MIC37xxx
LDOs.
Features









3A current capability
Low-dropout voltage
Low ground current
Accurate 1% guaranteed tolerance
Extremely fast transient response
Reverse-battery and “Load Dump” protection
Zero-current shutdown mode
Error flag signals output out-of-regulation
Also characterized for smaller loads with industryleading performance specifications
Applications





Battery-powered equipment
High-efficiency “Green” computer systems
Automotive electronics
High-efficiency linear power supplies
High-efficiency post-regulator for switching supply
Data sheets and support documentation can be found on
Micrel’s web site at: www.micrel.com.
Typical Application
Super βeta PNP is a 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
November 11, 2013
Revision 1.0
Micrel, Inc.
MIC29302HWU
Ordering Information
Part Number
MIC29302HWU
Junction Temp. Range
Voltage
Current
Package
–40° to +125°C
Adjustable
3.0A
5-Pin TO-263
Pin Configuration
5-Pin TO-263 (D2Pak) Adjustable Voltage
MIC29302HWU
Pin Description
Pin Number
Pin Name
1
EN: Enable, CMOS compatible control input. Logic high = enable, logic low = shutdown.
2
IN: Input power, supplies the current to the output power device
3, TAB
GND: TAB is also connected internally to the IC’s ground on D-PAK.
4
OUT: Output, the regulator output voltage
5
ADJ: Adjustable regulator feedback input that connects to the resistor voltage divider that is placed from
OUTPUT to GND in order to set the output voltage.
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MIC29302HWU
Absolute Maximum Ratings(1)
Operating Ratings(2)
(1)
Input Supply Voltage (VIN) ........................... –20V to +60V
Enable Input Voltage (VEN) ................................ –0.3V to VIN
Lead Temperature (soldering, 5sec.) ......................... 260°C
Power Dissipation ..................................... Internally Limited
Storage Temperature Range .................... –65°C to +150°C
ESD Rating.................................................................Note 3
Operating Junction Temperature .............. –40°C to +125°C
Maximum Operating Input Voltage ................................ 26V
Package Thermal Resistance
TO-263 (θJC)......................................................... 2°C/W
TO-263 (θJA) .................................................... 26.2°C/W
Electrical Characteristics(4, 13)
VIN = VOUT + 1V; IOUT = 10mA; TJ = 25°C. Bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted.
Parameter
Output Voltage
Line Regulation
Load Regulation
∆VO
∆T
Dropout Voltage
(∆VOUT = 1%(6))
Condition
Min.
IOUT = 10mA
10mA ≤ IOUT ≤ IFL, (VOUT + 1V) ≤ VIN ≤26V
(5)
Typ.
–1
1
–2
2
IOUT = 10mA, (VOUT + 1V) ≤ VIN ≤26V
%
0.2
1
%
Output Voltage
Temperature Coefficient.
20
100
ppm/°C
IOUT = 100mA
80
175
IOUT = 1.5A
250
IOUT = 3A
370
VIN = VOUT + 1V, 10mA ≤ IOUT ≤ 1.5A
(9)
IOUT = 1.5A,
10
IOUT = 3A
37
Ground Pin
Current at Dropout
VIN = 0.5V less than specified VOUT , IOUT = 10mA
1.7
Current Limit
VOUT = 0V(7)
4.5
en, Output Noise Voltage
(10Hz to 100kHz)
IL = 100mA
VEN = 0.4V
1.228
1.215
Reference Voltage
Reference Voltage
VREF ≤ VOUT ≤ (VIN – 1V), 2.3V ≤ VIN ≤ 26V,
10mA < IL ≤ 3A, TJ ≤ TJMAX
Adjust Pin Bias Current
Temperature Coefficient
Input Logic Voltage
Low (OFF)
High (ON)
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2.4
3
600
35
mA
mA
5.0
A
µV (rms)
20
µA
1.240
40
Note 10
mV
260
1.203
Adjust Pin Bias Current
Reference Voltage
Temperature Coefficient
%
0.5
8
Ground Current in
Shutdown
Units
0.06
(5,9)
IOUT = 750mA
Ground Current
(VIN = VOUT + 1V)
Max.
1.252
1.265
V
1.277
V
80
120
nA
20
ppm/°C
0.1
nA/°C
0.8
V
Revision 1.0
Micrel, Inc.
MIC29302HWU
Electrical Characteristics Continued(4, 13)
VIN = VOUT + 1V; IOUT = 10mA; TJ = 25°C. Bold values indicate –40°C ≤ TJ ≤ +125°C, unless noted.
Parameter
Condition
Min.
Typ.
Max.
100
600
750
VEN = 0.8V
0.8
2
4
Note 12
10
500
VEN = 26V
Enable Pin
Input Current
Regulator Output
Current in Shutdown
Units
µA
µA
Notes:
1.
Maximum positive supply voltage of 60V must be of limited duration (<100msec) and duty cycle (≤1%). The maximum continuous supply voltage is
26V. Exceeding the absolute maximum rating may damage the device.
2.
The device is not guaranteed to function outside its operating rating.
3.
Devices are ESD sensitive. Handling precautions recommended.
4.
Specification for packaged product only.
5.
Full load current (IFL) is defined as 3A for the MIC29302H.
6.
Dropout voltage is defined as the input-to-output differential when the output voltage drops to 99% of its normal value with VOUT + 1V applied to VIN.
7.
VIN = VOUT (nominal) + 1V. For example, use VIN = 4.3V for a 3.3V regulator or use 6V for a 5V regulator. Employ pulse-testing procedures to pin
current.
8.
Ground pin current is the regulator quiescent current. The total current drawn from the source is the sum of the load current plus the ground pin
current.
9.
Output voltage temperature coefficient is defined as the worst case voltage change divided by the total temperature range.
10. Thermal regulation is defined as the change in output voltage at a time T after a change in power dissipation is applied, excluding load or line
regulation effects. Specifications are for a 200mA load pulse at VIN = 20V (a 4W pulse) for T = 10ms.
11. Comparator thresholds are expressed in terms of a voltage differential at the Adjust terminal below the nominal reference voltage measured at 6V
input. To express these thresholds in terms of output voltage change, multiply by the error amplifier gain = VOUT/VREF = (R1 + R2)/R2. For example,
at a programmed output voltage of 5V, the Error output is guaranteed to go low when the output drops by 95mV x 5V/1.240V = 384mV. Thresholds
remain constant as a percent of VOUT as VOUT is varied, with the dropout warning occurring at typically 5% below nominal, 7.7% guaranteed.
12. VEN ≤ 0.8V and VIN ≤ 26V, VOUT = 0.
13. When used in dual supply systems where the regulator load is returned to a negative supply, the output voltage must be diode clamped to ground
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MIC29302HWU
Typical Characteristics
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MIC29302HWU
Typical Characteristics (Continued)
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MIC29302HWU
Functional Diagram
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MIC29302HWU
Thermal Design
Linear regulators are simple to use. The most
complicated design parameters to consider are thermal
characteristics. Thermal design requires the following
application-specific parameters:
Application Information
The MIC29302HWU is a high-performance low-dropout
voltage regulator suitable for moderate to high-current
voltage regulator applications. The 350mV to 425mV
typical dropout voltage at full load makes it especially
valuable in battery powered systems and as high
efficiency noise filters in “post-regulator” applications.
Unlike older NPN-pass transistor designs, where the
minimum dropout voltage is limited by the base-emitter
voltage drop and collector-emitter saturation voltage,
dropout performance of the PNP output of these devices
is limited merely by the low VCE saturation voltage.

Maximum ambient temperature, TA

Output Current, IOUT

Output Voltage, VOUT

Input Voltage, VIN
First, we calculate the power dissipation of the regulator
from these numbers and the device parameters from this
datasheet.
A trade-off for the low-dropout voltage is a varying base
driver requirement. But Micrel’s Super ßeta PNP®
process reduces this drive requirement to merely 1% of
the load current.
PD  IOUT 1.01 VIN  VOUT 
The MIC29302HWU regulator is fully protected from
damage due to fault conditions. Current limiting is
provided. This limiting is linear; output current under
overload conditions is constant. Thermal shutdown
disables the device when the die temperature exceeds
the 125°C maximum safe operating temperature. Line
transient protection allows device (and load) survival
even when the input voltage spikes between –20V and
+60V. When the input voltage exceeds approximately
40V, the over voltage sensor disables the regulator. The
output structure of these regulators allows voltages in
excess of the desired output voltage to be applied
without reverse current flow. The MIC29302HWU
versions offer a logic level ON/OFF control: when
disabled, the devices draw nearly zero current.
Eq. 1
where the ground current is approximated by 1% of IOUT.
Then the heat sink thermal resistance is determined with
T
 TA
SA  JMAX
 JC  CS 
PD
Eq. 2
:
T
 TA
SA  JMAX
 JC  CS 
PD
Eq. 2
where TJMAX ≤ 125°C and θCS is between 0 and
2°C/W.
For example, given an expected maximum ambient
temperature (TA) of 75C with VIN = 3.3V, VOUT =
2.5V, and IOUT = 1.5A, first calculate the expected PD
using Eq. 3:
PD=(3.3V–2.5V)1.5A–(3.3V)(0.016A)=1.1472W
Eq. 3
Figure 1. Linear Regulators Require Only
Two Capacitors for Operation
Next, calcualte the junction temperature for the expected
power dissipation.
TJ=(θJA×PD)+TA=(56C/W×1.1472W)+75C
=139.24C
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Eq. 4
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Micrel, Inc.
MIC29302HWU
Minimum Load Current
The MIC29300HWU is specified between finite loads. If
the output current below 7mA, leakage currents
dominate and the output voltage rises.
Then determine the maximum power dissipation allowed
that would not exceed the IC’s maximum junction
temperature (125C) without the useof a heat sink by:
Adjustable Regulator Design
The MIC20302HWU allows programming the output
voltage anywhere between 1.25V and the 25V. Two
resistors are used. The resistor values are calculated by
V

Eq 6:
R 1  R 2   OUT  1
1.240


PD(MAX) = (TJ(MAX)–TA)/θJA
= (125C–75C)/(56C/W) = 0.893W
Eq. 5
Capacitor Requirements
For stability and to minimize output noise, a capacitor on
the regulator output is necessary. The value of this
capacitor is dependent upon the output current; lower
currents allow smaller capacitors. The MIC29302HWU is
stable with minimum of 100µF. This capacitor need not
be an expensive low ESR type: aluminum electrolytics
are adequate. In fact, extremely low ESR capacitors may
contribute to instability. Tantalum capacitors are
recommended for systems where fast load transient
response is important.
V

R 1  R 2   OUT  1
1.240


where VOUT is the desired output voltage. Figure 3 shows
component definition. Applications with widely varying
load currents may scale the resistors to draw the
minimum load current required for proper operation (see
“Minimum Load Current” sub-section).
Enable Input
MIC29302HWU features an enable (EN) input that
allows ON/OFF control of the device. Special design
allows “zero” current drain when the device is disabled—
only microamperes of leakage current flows. The EN
input has TTL/CMOS compatible thresholds for simple
interfacing with logic, or may be directly tied to ≤30V.
Enabling the regulator requires approximately 20µA of
current.
Where the regulator is powered from a source with high
AC impedance, a 0.1µF capacitor connected between
Input and GND is recommended. This capacitor should
have good characteristics to above 250kHz.
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MIC29302HWU
Package Information(Error! Reference source not found.)
5-Pin TO-263 (U)
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 makes no representations or warranties with respect to the accuracy or completeness of the information furnished in this data sheet. 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.
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© 2013 Micrel, Incorporated.
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