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LP2953QML Adjustable Micropower Low-Dropout Voltage Regulators
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1FEATURES DESCRIPTION
The LP2953A is a micropower voltage regulator with
2• Output Voltage Adjusts from 1.23V to 29V very low quiescent current (130 μA typical at 1 mA
• Ensured 250 mA Output Current load) and very low dropout voltage (typ. 60 mV at
• Extremely Low Quiescent Current light load and 470 mV at 250 mA load current). It is
ideally suited for battery-powered systems.
• Low Dropout Voltage Furthermore, the quiescent current increases only
• Extremely Tight Line and Load Regulation slightly at dropout, which prolongs battery life.
• Very Low Temperature Coefficient The LP2953A retains all the desirable characteristics
• Current and Thermal Limiting of the LP2951, but offers increased output current,
• Reverse Battery Protection additional features, and an improved shutdown
function.
• 50 mA (Typical) Output Pulldown Crowbar
• Auxiliary Comparator Included with CMOS/TTL The internal crowbar pulls the output down quickly
when the shutdown is activated.
Compatible Output Levels. Can be used for
Fault Detection, Low Input Line Detection, etc. The error flag goes low if the output voltage drops out
of regulation.
APPLICATIONS Reverse battery protection is provided.
• High-Efficiency Linear Regulator The internal voltage reference is made available for
• Regulator with Under-Voltage Shutdown external use, providing a low-T.C. reference with very
• Low Dropout Battery-Powered Regulator good line and load regulation.
• Snap-ON/Snap-OFF Regulator
Connection Diagram
Note: Pins 1, 8, 9, 16 must be shorted together on customer PC board application
Figure 1. 16-Pin CFP Package
1Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
2All trademarks are the property of their respective owners.
PRODUCTION DATA information is current as of publication date. Copyright © 2010–2013, Texas Instruments Incorporated
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
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Block Diagram
Figure 2. LP2953
These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the MOS gates.
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Absolute Maximum Ratings(1)
Storage Temperature Range −65°C ≤TA≤+150°C
Operating Temperature Range −55°C ≤TA≤+125°C
Maximum Junction Temperature +150°C
Lead Temp. (Soldering, 5 seconds) 260°C
Power Dissipation(2) Internally Limited
Input Supply Voltage −20V to +30V
Feedback Input Voltage(3) −0.3V to +5V
Comparator Input Voltage(4) −0.3V to +30V
Shutdown Input Voltage(4) −0.3V to +30V
Comparator Output Voltage(4) −0.3V to +30V
16LD CFP "WG" (device 01) (Still Air) 134°C/W
16LD CFP "WG" (device 01) (500LF/Min Air flow) 81°C/W
θJA 16LD CFP "GW" (device 02) (Still Air) 140°C/W
Thermal Resistance 16LD CFP "GW" (device 02) (500LF/Min Air flow) 90°C/W
16LD CFP "WG" (device 01)(5) 7°C/W
θJC 16LD CFP "GW" (device 02) 15°C/W
16LD CFP "WG" (device 01) 360mg
Package Weight (Typical) 16LD CFP "GW" (device 02) 410mg
ESD Rating(6) 2 KV
(1) Abs. Max Ratings indicate limits beyond which damage to the device may occur. Operating ratings indicate conditions for which the
device is functional, but do not ensure specific performance limits. For ensured specifications and test conditions, see Electrical
Characteristics. The specifications apply only for the test conditions listed. Some performance characteristics may degrade when the
device is not operated under the listed test conditions.
(2) The maximum power dissipation must be derated at elevated temperatures and is dictated by TJmax (maximum junction temperature),
θJA (package junction to ambient thermal resistance), and TA(ambient temperature). The maximum allowable power dissipation at any
temperature is PDmax = (TJmax - TA)/θJA or the number given in the Absolute Maximum Ratings, whichever is lower.
(3) 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.
(4) May exceed the input supply voltage.
(5) The package material for these devices allows much improved heat transfer over our standard ceramic packages. In order to take full
advantage of this improved heat transfer, heat sinking must be provided between the package base (directly beneath the die), and either
metal traces on, or thermal vias through, the printed circuit board. Without this additional heat sinking, device power dissipation must be
calculated using θJA, rather than θJC, thermal resistance. It must not be assumed that the device leads will provide substantial heat
transfer out the package, since the thermal resistance of the leadframe material is very poor, relative to the material of the package
base. The stated θJC thermal resistance is for the package material only, and does not account for the additional thermal resistance
between the package base and the printed circuit board. The user must determine the value of the additional thermal resistance and
must combine this with the stated value for the package, to calculate the total allowed power dissipation for the device.
(6) Human body model, 1.5 KΩin series with 100 pF.
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Quality Conformance Inspection
Table 1. Mil-Std-883, Method 5005 - Group A
Subgroup Description Temp (°C)
1 Static tests at +25
2 Static tests at +125
3 Static tests at -55
4 Dynamic tests at +25
5 Dynamic tests at +125
6 Dynamic tests at -55
7 Functional tests at +25
8A Functional tests at +125
8B Functional tests at -55
9 Switching tests at +25
10 Switching tests at +125
11 Switching tests at -55
12 Settling time at +25
13 Settling time at +125
14 Settling time at -55
LP2953A Electrical Characteristics DC Parameters
The following conditions apply, unless otherwise specified. VI= 6V, IL= 1mA, CL= 2.2µF, VO= 5V
Feedback pin is tied to 5V Tap pin. Output pin is tied to Output Sense Pin. Sub-
Parameter Test Conditions Notes Min Max Units groups
4.975 5.025 V 1
VOOutput Voltage 4.94 5.06 V 2, 3
1mA ≤IL≤250mA 4.93 5.07 V 1, 2, 3
ΔVO/ VOOutput Voltage Line VI= 6V to 30V 0.1 % 1
Regulation 0.2 % 2, 3
0.16 % 1
IL= 1mA to 250mA 0.2 % 2, 3
Output Voltage Load
ΔVO/ VORegulation 0.16 % 1
IL= 0.1mA to 1mA 0.2 % 2, 3
100 mV 1
IL= 1mA See(1) 150 mV 2, 3
300 mV 1
IL= 50mA See(1) 420 mV 2, 3
VI- VODropout Voltage 400 mV 1
IL= 100mA See(1) 520 mV 2, 3
600 mV 1
IL= 250mA See(1) 800 mV 2, 3
(1) Dropout voltage is defined as the input to output differential at which the output voltage drops 100 mV below the value measured with a
1V differential. At very low values of programmed output voltage, the input voltage minimum of 2V (2.3V over temperature) must be
observed.
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LP2953A Electrical Characteristics DC Parameters (continued)
The following conditions apply, unless otherwise specified. VI= 6V, IL= 1mA, CL= 2.2µF, VO= 5V
Feedback pin is tied to 5V Tap pin. Output pin is tied to Output Sense Pin. Sub-
Parameter Test Conditions Notes Min Max Units groups
170 µA 1
IL= 1mA See(2) 200 µA 2, 3
2.0 mA 1
IL= 50mA See(2) 2.5 mA 2, 3
IGnd Ground Pin Current 6.0 mA 1
IL= 100mA See(2) 8.0 mA 2, 3
28 mA 1
IL= 250mA See(2) 33 mA 2, 3
210 µA 1
Ground Pin Current at
IGnd VI= 4.5V, IL= 100µA See(2)
Dropout 240 µA 2, 3
Ground Pin Current at
IGnd See(2)(3) 140 µA 1
Shutdown 500 mA 1
ILimit Current Limit VO= 0V 530 mA 2, 3
ΔVO/ΔPDThermal Regulation See(4) 0.2 %/W 1
1.215 1.245 V 1
VRef Reference Voltage See(5) 1.205 1.255 V 2, 3
0.1 % 1
VI= 2.5V to 6V 0.2 % 2, 3
Reference Voltage Line
ΔVRef / VRef Regulation 0.1 % 1
VI= 6V to 30V 0.2 % 2, 3
ΔVRef / VRef 0.4 % 1
Reference Voltage Load IRef = 0 to 200µA
Regulation 0.6 % 2, 3
40 nA 1
Feedback Pin Bias
IB FB Current 60 nA 2, 3
30 mA 1
Output "Off" Pulldown
IO Sink See(6)
Current 20 mA 2, 3
(2) Ground pin current is the regulator quiescent current. The total current drawn from the source is the sum of the ground pin current,
output load current, and current through the external resistive divider (if used).
(3) VShutdown ≤1.1V, VO= VO(Nom).
(4) Thermal regulation is the change in output voltage at a time T after a change in power dissipation, excluding load or line regulation
effects. Specifications are for a 200 mA load pulse at VI= VO(Nom)+15V (3W pulse) for T = 10 mS.
(5) VRef ≤VO≤(VI−1V), 2.3V ≤VI≤30V, 100 μA≤IL≤250 mA.
(6) VShutdown ≤1.1V, VO= VO(Nom).
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LP2953A Electrical Characteristics Dropout Detection Comparator Parameters
The following conditions apply, unless otherwise specified. VI= 6V, IL= 1mA, CL= 2.2µF, VO= 5V
Feedback pin is tied to 5V Tap pin. Output pin is tied to Output Sense Pin. Sub-
Parameter Test Conditions Notes Min Max Units groups
1.0 µA 1
IOH Output "High" Leakage VOH = 30V 2.0 µA 2, 3
250 mV 1
VOL Output "Low" Voltage VI= 4V, IOComp = 400µA 400 mV 2, 3
-320 -150 mV 1
VTh Max Upper Threshold Voltage See(1) -380 -130 mV 2
-380 -120 mV 3
-450 -280 mV 1
VTh Min Lower Threshold Voltage See(1) -640 -180 mV 2
-640 -155 mV 3
(1) Comparator thresholds are expressed in terms of a voltage differential at the Feedback terminal below the nominal VRef measured at VI
= VO(Nom) + 1V. To express these thresholds in terms of output voltage change, multiply by the Error amplifier gain, which is VO/ VRef =
(R1 + R2)/R2 (refer to Figure 31).
LP2953A Electrical Characteristics SHUTDOWN Input Parameters
The following conditions apply, unless otherwise specified. VI= 6V, IL= 1mA, CL= 2.2µF, VO= 5V
Feedback pin is tied to 5V Tap pin. Output pin is tied to Output Sense Pin. Sub-
Parameter Test Conditions Notes Min Max Units groups
-7.5 7.5 mV 1
VIO Input Offset Voltage Referred to VRef -10 10 mV 2
-12 12 mV 3
-30 30 nA 1
IIB Input Bias Current VIComp = 0 to 5V -50 50 nA 2
-75 75 nA 3
LP2953A Electrical Characteristics Auxillary Comparator Parameters
The following conditions apply, unless otherwise specified. VI= 6V, IL= 1mA, CL= 2.2µF, VO= 5V
Feedback pin is tied to 5V Tap pin. Output pin is tied to Output Sense Pin. Sub-
Parameter Test Conditions Notes Min Max Units groups
-7.5 7.5 mV 1
VIO Input Offset Voltage Referred to VRef -10 10 mV 2
-12 12 mV 3
-30 30 nA 1
IIB Input Bias Current VIComp = 0 to 5V -50 50 nA 2
-75 75 nA 3
1.0 µA 1
IOH Output "High" Leakage VOH = 30V, VIComp = 1.3V 2.0 µA 2
2.2 µA 3
250 mV 1
VOL Output "Low" Voltage VIComp = 1.1V, IOComp = 400µA 400 mV 2
420 mV 3
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LP2953A Electrical Characteristics DC Drift Parameters
The following conditions apply, unless otherwise specified. VI= 6V, IL= 1mA, CL= 2.2µF, VO= 5V
Feedback pin is tied to 5V Tap pin. Output pin is tied to Output Sense Pin.
Δcalculations performed on QMLV devices at group B , subgroup 5. Sub-
Parameter Test Conditions Notes Min Max Units groups
IL= 1mA -12 12 % 1
IL= 50mA -12 12 % 1
VI- VODropout Voltage IL= 100mA -12 12 % 1
IL= 250mA -12 12 % 1
IL= 1mA, ±5µA or ±10% whichever is -5.0 5.0 µA 1
greater
IL= 50mA, ±5µA or ±10% whichever is -5.0 5.0 µA 1
greater
IGnd Ground Pin Current IL= 100mA, ±5µA or ±10% whichever is -5.0 5.0 µA 1
greater
IL= 250mA, ±5µA or ±10% whichever is -5.0 5.0 µA 1
greater
Ground Pin Current at VI= 4.5V, IL= 100µA,
IGnd -5.0 5.0 µA 1
Dropout ±5µA or ±10% whichever is greater
Ground Pin Current at
IGnd ±5µA or ±10% whichever is greater -5.0 5.0 µA 1
Shutdown Referred to VRefSHUTDOWN Input -1.0 1.0 mV 1
VIO Input Offset Voltage Referred to VRef Auxillary Comparator -1.0 1.0 mV 1
VIComp = 0 to 5V SHUTDOWN Input -5.0 5.0 nA 1
IIB Input Bias Current VIComp = 0 to 5V Auxillary Comparator -5.0 5.0 nA 1
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Typical Performance Characteristics
Unless otherwise specified: VI= 6V, IL= 1 mA, CL= 2.2 μF, VSD = 3V, TA= 25°C, VO= 5V.
Quiescent Current Quiescent Current
Figure 3. Figure 4.
Ground Pin Current vs Load Ground Pin Current
Figure 5. Figure 6.
Ground Pin Current Output Noise Voltage
Figure 7. Figure 8.
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Typical Performance Characteristics (continued)
Unless otherwise specified: VI= 6V, IL= 1 mA, CL= 2.2 μF, VSD = 3V, TA= 25°C, VO= 5V.
Ripple Rejection Ripple Rejection
Figure 9. Figure 10.
Ripple Rejection Line Transient Response
Figure 11. Figure 12.
Line Transient Response Output Impedance
Figure 13. Figure 14.
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Typical Performance Characteristics (continued)
Unless otherwise specified: VI= 6V, IL= 1 mA, CL= 2.2 μF, VSD = 3V, TA= 25°C, VO= 5V.
Load Transient Response Load Transient Response
Figure 15. Figure 16.
Dropout Characteristics Enable Transient
Figure 17. Figure 18.
Short-Circuit Output Current
Enable Transient and Maximum Output Current
Figure 19. Figure 20.
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Typical Performance Characteristics (continued)
Unless otherwise specified: VI= 6V, IL= 1 mA, CL= 2.2 μF, VSD = 3V, TA= 25°C, VO= 5V.
Feedback Bias Current Feedback Pin Current
Figure 21. Figure 22.
Error Output Comparator Sink Current
Figure 23. Figure 24.
Dropout Detection Comparator
Divider Resistance Threshold Voltages
Figure 25. Figure 26.
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Typical Performance Characteristics (continued)
Unless otherwise specified: VI= 6V, IL= 1 mA, CL= 2.2 μF, VSD = 3V, TA= 25°C, VO= 5V.
Thermal Regulation Minimum Operating Voltage
Figure 27. Figure 28.
Dropout Voltage
Figure 29.
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APPLICATION HINTS
Ground Pins
For the LP2953 16–Pin Ceramic SOIC, Pins 1, 8, 9, 16 MUST BE SHORTED TOGETHER ON CUSTOMER'S
P.C. BOARD APPLICATION.
Heatsink Requirements
The maximum allowable power dissipation for the LP2953 is limited by the maximum junction temperature
(+150°C) and the two parameters that determine how quickly heat flows away from the die: the ambient
temperature and the junction-to-ambient thermal resistance of the part.
The military parts which are manufactured in ceramic DIP packages contain a KOVAR lead frame (unlike the
industrial parts, which have a copper lead frame). The KOVAR material is necessary to attain the hermetic seal
required in military applications.
The KOVAR lead frame does not conduct heat as well as copper, which means that the PC board copper can
not be used to significantly reduce the overall junction-to-ambient thermal resistance.
The power dissipation calculations are done using a fixed value for θ(J–A), the junction-to-ambient thermal
resistance, of 134°C/W and can not be changed by adding copper foil patterns to the PC board. This leads to an
important fact: The maximum allowable power dissipation in any application using the LP2953 is dependent only
on the ambient temperature:
(1)
External Capacitors
A 2.2 μF (or greater) capacitor is required between the output pin and ground to assure stability when the output
is set to 5V. Without this capacitor, the part will oscillate. Most type of tantalum or aluminum electrolytics will
work here. Film types will work, but are more expensive. Many aluminum electrolytics contain electrolytes which
freeze at −30°C, which requires the use of solid tantalums below −25°C. The important parameters of the
capacitor are an ESR of about 5Ωor less and a resonant frequency above 500 kHz (the ESR may increase by a
factor of 20 or 30 as the temperature is reduced from 25°C to −30°C). The value of this capacitor may be
increased without limit.
At lower values of output current, less output capacitance is required for stability. The capacitor can be reduced
to 0.68 μF for currents below 10 mA or 0.22 μF for currents below 1 mA.
Programming the output for voltages below 5V runs the error amplifier at lower gains requiring more output
capacitance for stability. At 3.3V output, a minimum of 4.7 μF is required. For the worst-case condition of 1.23V
output and 250 mA of load current, a 6.8 μF (or larger) capacitor should be used.
A 1 μF capacitor should be placed from the input pin to ground if there is more than 10 inches of wire between
the input and the AC filter capacitor or if a battery input is used.
Stray capacitance to the Feedback terminal can cause instability. This problem is most likely to appear when
using high value external resistors to set the output voltage. Adding a 100 pF capacitor between the Output and
Feedback pins and increasing the output capacitance to 6.8 μF (or greater) will cure the problem.
Minimum Load
When setting the output voltage using an external resistive divider, a minimum current of 1 μA is recommended
through the resistors to provide a minimum load.
It should be noted that a minimum load current is specified in several of the electrical characteristic test
conditions, so this value must be used to obtain correlation on these tested limits.
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Figure 30. Power Derating Curve for LP2953
Programming the Output Voltage
The regulator may be pin-strapped for 5V operation using its internal resistive divider by tying the Output and
Sense pins together and also tying the Feedback and 5V Tap pins together.
Alternatively, it may be programmed for any voltage between the 1.23V reference and the 30V maximum rating
using an external pair of resistors (see Figure 31). The complete equation for the output voltage is:
(2)
where VREF is the 1.23V reference and IFB is the Feedback pin bias current (−20 nA typical). The minimum
recommended load current of 1 μA sets an upper limit of 1.2 MΩon the value of R2 in cases where the regulator
must work with no load (see Minimum Load). IFB will produce a typical 2% error in VOwhich can be eliminated at
room temperature by trimming R1. For better accuracy, choosing R2 = 100 kΩwill reduce this error to 0.17%
while increasing the resistor program current to 12 μA. Since the typical quiescent current is 120 μA, this added
current is negligible.
* See Application Hints
** Drive with TTL-low to shut down
Figure 31. Adjustable Regulator
Dropout Voltage
The dropout voltage of the regulator is defined as the minimum input-to-output voltage differential required for the
output voltage to stay within 100 mV of the output voltage measured with a 1V differential. The dropout voltage is
independent of the programmed output voltage.
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Dropout Detection Comparator
This comparator produces a logic "LOW" whenever the output falls out of regulation by more than about 5%. This
figure results from the comparator's built-in offset of 60 mV divided by the 1.23V reference (refer to Block
Diagram). The 5% low trip level remains constant regardless of the programmed output voltage. An out-of-
regulation condition can result from low input voltage, current limiting, or thermal limiting.
Figure 32 gives a timing diagram showing the relationship between the output voltage, the ERROR output, and
input voltage as the input voltage is ramped up and down to a regulator programmed for 5V output. The ERROR
signal becomes low at about 1.3V input. It goes high at about 5V input, where the output equals 4.75V. Since the
dropout voltage is load dependent, the input voltage trip points will vary with load current. The output voltage
trip point does not vary.
The comparator has an open-collector output which requires an external pull-up resistor. This resistor may be
connected to the regulator output or some other supply voltage. Using the regulator output prevents an invalid
"HIGH" on the comparator output which occurs if it is pulled up to an external voltage while the regulator input
voltage is reduced below 1.3V. In selecting a value for the pull-up resistor, note that while the output can sink
400 μA, this current adds to battery drain. Suggested values range from 100 kΩto 1 MΩ. This resistor is not
required if the output is unused.
When VIN ≤1.3V, the error flag pin becomes a high impedance, allowing the error flag voltage to rise to its pull-
up voltage. Using VOUT as the pull-up voltage (rather than an external 5V source) will keep the error flag voltage
below 1.2V (typical) in this condition. The user may wish to divide down the error flag voltage using equal-value
resistors (10 kΩsuggested) to ensure a low-level logic signal during any fault condition, while still allowing a valid
high logic level during normal operation.
* In shutdown mode, ERROR will go high if it has been pulled up to an external supply. To avoid this invalid
response, pull up to regulator output.
** Exact value depends on dropout voltage. (See Application Hints)
Figure 32. ERROR Output Timing
Output Isolation
The regulator output can be left connected to an active voltage source (such as a battery) with the regulator input
power shut off, as long as the regulator ground pin is connected to ground. If the ground pin is left floating,
damage to the regulator can occur if the output is pulled up by an external voltage source.
Reducing Output Noise
In reference applications it may be advantageous to reduce the AC noise present on the output. One method is
to reduce regulator bandwidth by increasing output capacitance. This is relatively inefficient, since large
increases in capacitance are required to get significant improvement.
Noise can be reduced more effectively by a bypass capacitor placed across R1 (refer to Figure 31). The formula
for selecting the capacitor to be used is:
(3)
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This gives a value of about 0.1 μF. When this is used, the output capacitor must be 6.8 μF (or greater) to
maintain stability. The 0.1 μF capacitor reduces the high frequency gain of the circuit to unity, lowering the output
noise from 260 μV to 80 μV using a 10 Hz to 100 kHz bandwidth. Also, noise is no longer proportional to the
output voltage, so improvements are more pronounced at high output voltages.
Auxiliary Comparator
The LP2953 contains an auxiliary comparator whose inverting input is connected to the 1.23V reference. The
auxiliary comparator has an open-collector output whose electrical characteristics are similar to the dropout
detection comparator. The non-inverting input and output are brought out for external connections.
SHUTDOWN Input
A logic-level signal will shut off the regulator output when a "LOW" (<1.2V) is applied to the Shutdown input.
To prevent possible mis-operation, the Shutdown input must be actively terminated. If the input is driven from
open-collector logic, a pull-up resistor (20 kΩto 100 kΩrecommended) should be connected from the Shutdown
input to the regulator input.
If the Shutdown input is driven from a source that actively pulls high and low (like an op-amp), the pull-up resistor
is not required, but may be used.
If the shutdown function is not to be used, the cost of the pull-up resistor can be saved by simply tying the
Shutdown input directly to the regulator input.
IMPORTANT: Since the Absolute Maximum Ratings state that the Shutdown input can not go more than 0.3V
below ground, the reverse-battery protection feature which protects the regulator input is sacrificed if the
Shutdown input is tied directly to the regulator input.
If reverse-battery protection is required in an application, the pull-up resistor between the Shutdown input and the
regulator input must be used.
Typical Applications
Figure 33. Basic 5V Regulator
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* Output voltage equals +VIN minum dropout voltage, which varies with output current. Current limits at a maximum of
380 mA (typical).
** Select R1 so that the comparator input voltage is 1.23V at the output voltage which corresponds to the desired fault
current value.
Figure 34. 5V Current Limiter with Load Fault Indicator
Figure 35. Low T.C. Current Sink
* Connect to Logic or μP control inputs.
LOW BATT flag warns the user that the battery has discharged down to about 5.8V, giving the user time to recharge
the battery or power down some hardware with high power requirements. The output is still in regulation at this time.
OUT OF REGULATION flag indicates when the battery is almost completely discharged, and can be used to initiate a
power-down sequence.
Figure 36. 5V Regulator with Error Flags for
LOW BATTERY and OUT OF REGULATION
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Product Folder Links: LP2953QML LP2953QML-SP
LP2953QML, LP2953QML-SP
www.ti.com
SNVS395C –NOVEMBER 2010–REVISED APRIL 2013
The circuit switches to the NI-CAD backup battery when the main battery voltage drops below about 5.6V, and returns
to the main battery when its voltage is recharged to about 6V.
The 5V MAIN output powers circuitry which requires no backup, and the 5V MEMORY output powers critical circuitry
which can not be allowed to lose power.
* The BATTERY LOW flag goes low whenever the circuit switches to the NI-CAD backup battery.
Figure 37. 5V Battery Powered Supply with Backup and Low Battery Flag
Figure 38. 5V Regulator with Timed Power-On Reset
* RT= 1 MEG, CT= 0.1 μF
Figure 39. Timing Diagram for Timed Power-On Reset
Copyright © 2010–2013, Texas Instruments Incorporated Submit Documentation Feedback 19
Product Folder Links: LP2953QML LP2953QML-SP
LP2953QML, LP2953QML-SP
SNVS395C –NOVEMBER 2010–REVISED APRIL 2013
www.ti.com
* Connect to Logic or μP control inputs.
OUTPUT has SNAP-ON/SNAP-OFF feature.
LOW BATT flag warns the user that the battery has discharged down to about 5.8V, giving the user time to recharge
the battery or shut down hardware with high power requirements. The output is still in regulation at this time.
OUT OF REGULATION flag goes low if the output goes below about 4.7V, which could occur from a load fault.
OUTPUT has SNAP-ON/SNAP-OFF feature. Regulator snaps ON at about 5.7V input, and OFF at about 5.6V.
Figure 40. 5V Regulator with Error Flags for
LOW BATTERY and OUT OF REGULATION
with SNAP-ON/SNAP-OFF Output
Figure 41. 5V Regulator with Timed Power-On Reset, Snap-On/Snap-Off Feature and Hysteresis
Td = (0.28) RC = 28 ms for components shown.
Figure 42. Timing Diagram
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www.ti.com
SNVS395C –NOVEMBER 2010–REVISED APRIL 2013
REVISION HISTORY SECTION
Released Revision Section Changes
1 MDS data sheet converted into one Corp. data
11/30/2010 A New Release, Corporate format sheet format. MNLP2953AM-X Rev 1A1 will be
archived.
Ordering Information — entered new 'GW' devices.
Ordering Information, Absolute Maximum Absolute Maximum Ratings — added new Theta JA
09/01/2011 B Ratings and Theta JC numbers. LP2953QML Rev A will be
archived.
Connection Diagrams and Applications Notes :
Added: * Pins 1, 8, 9, 16 MUST BE SHORTED
09/20/2012 C Connection Diagrams, Application Notes TOGETHER ON CUSTOMER'S P.C. BOARD
APPLICATION. Rev B will be archived.
Copyright © 2010–2013, Texas Instruments Incorporated Submit Documentation Feedback 21
Product Folder Links: LP2953QML LP2953QML-SP
LP2953QML, LP2953QML-SP
SNVS395C –NOVEMBER 2010–REVISED APRIL 2013
www.ti.com
REVISION HISTORY
Changes from Revision B (April 2013) to Revision C Page
• Changed layout of National Data Sheet to TI format .......................................................................................................... 17
22 Submit Documentation Feedback Copyright © 2010–2013, Texas Instruments Incorporated
Product Folder Links: LP2953QML LP2953QML-SP
PACKAGE OPTION ADDENDUM
www.ti.com 22-Apr-2013
Addendum-Page 1
PACKAGING INFORMATION
Orderable Device Status
(1)
Package Type Package
Drawing Pins Package
Qty Eco Plan
(2)
Lead/Ball Finish MSL Peak Temp
(3)
Op Temp (°C) Top-Side Markings
(4)
Samples
5962-9233602QXA ACTIVE CFP NAC 16 42 TBD Call TI Call TI -55 to 125 LP2953AMGW
/883 Q
5962-92336
02QXA ACO
02QXA >T
5962-9233602VXA ACTIVE CFP NAC 16 42 TBD Call TI Call TI -55 to 125 LP2953AMGW-
QMLV Q
5962-92336
02VXA ACO
02VXA >T
LP2953AMGW-QMLV ACTIVE CFP NAC 16 42 TBD Call TI Call TI -55 to 125 LP2953AMGW-
QMLV Q
5962-92336
02VXA ACO
02VXA >T
LP2953AMGW/883 ACTIVE CFP NAC 16 42 TBD Call TI Call TI -55 to 125 LP2953AMGW
/883 Q
5962-92336
02QXA ACO
02QXA >T
(1) The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability
information and additional product content details.
TBD: The Pb-Free/Green conversion plan has not been defined.
Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that
lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes.
Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between
the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above.
Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight
in homogeneous material)
PACKAGE OPTION ADDENDUM
www.ti.com 22-Apr-2013
Addendum-Page 2
(3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature.
(4) Multiple Top-Side Markings will be inside parentheses. Only one Top-Side Marking contained in parentheses and separated by a "~" will appear on a device. If a line is indented then it is a
continuation of the previous line and the two combined represent the entire Top-Side Marking for that device.
Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information
provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and
continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals.
TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis.
OTHER QUALIFIED VERSIONS OF LP2953QML, LP2953QML-SP :
•Military: LP2953QML
•Space: LP2953QML-SP
NOTE: Qualified Version Definitions:
•Military - QML certified for Military and Defense Applications
•Space - Radiation tolerant, ceramic packaging and qualified for use in Space-based application
MECHANICAL DATA
NAC0016A
www.ti.com
WG16A (RevG)
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