DATA SHEET
LP387x 0.8-A Fast Ultra-Low-Dropout Linear Regulators
1 Features
- Input Voltage: 2.5 V to 7 V
- Ultra-Low-Dropout Voltage
- Low Ground Pin Current
- Load Regulation of 0.04%
- 10-nA Quiescent Current in Shutdown Mode
- Specified Output Current of 0.8-A DC
- Output Voltage Accuracy ±1.5%
- ERROR Flag Indicates Output Status
- SENSE Option Improves Load Regulation
- Minimum Output Capacitor Requirements
- Overtemperature/Overcurrent Protection
- −40°C to +125°C Junction Temperature Range
2 Applications
- Microprocessor Power Supplies
- GTL, GTL+, BTL, and SSTL Bus Terminators
- Power Supplies for DSPs
- SCSI Terminator
- Post Regulators
- High-Efficiency Linear Regulators
- Battery Chargers
- Other Battery-Powered Applications
3 Description
The LP3871 and LP3874 series of fast ultra-low-dropout linear regulators operate from a 2.5-V to 7-V input supply. Wide range of preset output voltage options are available. These ultra-low-dropout linear regulators respond very quickly to step changes in load, which makes them suitable for low voltage microprocessor applications. The devices are developed on a CMOS process which allows low quiescent current operation independent of output load current. This CMOS process also allows the LP3871 and LP3874 to operate under extremely low dropout conditions.
Dropout Voltage: Ultra-low-dropout voltage; typically 24 mV at 80-mA load current and 240 mV at 0.8-A load current.
Ground Pin Current: Typically 6 mA at 0.8-A load current.
Shutdown Mode: Typically 10-nA quiescent current when the SD pin is pulled low.
ERROR Flag: ERROR flag goes low when the output voltage drops 10% below nominal value.
SENSE: SENSE pin improves regulation at remote loads.
Precision Output Voltage: Multiple output voltage options are available ranging from 1.8 V to 5 V with a ensured accuracy of ±1.5% at room temperature, and ±3% over all conditions (varying line, load, and temperature).
Device Information(1)
| PART NUMBER | PACKAGE | BODY SIZE (NOM) |
|---|---|---|
| LP3871 LP3874 |
SOT-223 (5) | 6.50 mm x 3.56 mm |
| DDPAK/ TO-263 (5) | 10.16 mm x 8.42 mm |
- For all available packages, see the orderable addendum at the end of the data sheet.
Typical Applications
*SD and ERROR pins must be pulled high through a 10-kΩ pullup resistor. Connect the ERROR pin to ground if this function is not used. See Application and Implementation for more information.
*SD must be pulled high through a 10-kΩ pullup resistor. See Application and Implementation for more information.
4 Revision History
Changes from G Revision (April 2013) to H Revision
- Added Pin Configuration and Functions section, ESD Rating table, Feature Description , Device Functional Modes, Application and Implementation, Power Supply Recommendations, Layout, Device and Documentation Support , and Mechanical, Packaging, and Orderable Information sections; conform pin names in graphics to TI nomenclatureGo
- Deleted Lead temperature row - information in POA Go
- Deleted Heatsinking subsections regarding specific packages as specs have been updated (see Thermal Information). Go
- Changed layout examples to eliminate obsolete thermal-value references Go
Changes from F Revision (April 2013) to G Revision
- Changed layout of National Data Sheet to TI formatGo
5 Pin Configuration and Functions
KTT Package
5-Pin DDPAK/TO-263
Top View
NC Package
5-Pin SOT-223
Top View
Pin Functions
| PIN | TYPE | DESCRIPTION | ||||
|---|---|---|---|---|---|---|
| NAME | LP3871 | LP3874 | ||||
| SOT-223 | DDPAK/TO-263 | SOT-223 | DDPAK/TO-263 | |||
| ERROR | 4 | 5 | — | — | O | ERROR Flag |
| GND | 5 | 3 | 5 | 3 | GND | Ground |
| IN | 2 | 2 | 2 | 2 | I | Input voltage |
| OUT | 3 | 4 | 3 | 4 | O | Output voltage |
| SD | 1 | 1 | 1 | 1 | I | Shutdown |
| SENSE | — | — | 4 | 5 | I | Remote voltage sense |
6 Specifications
6.1 Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)(2)| MIN | MAX | UNIT | |
|---|---|---|---|
| Input supply voltage (survival) | −0.3 | 7.5 | V |
| Shutdown input voltage (survival) | −0.3 | 7.5 | V |
| Output voltage (survival)(3)(4) | −0.3 | 6 | V |
| IOUT (survival) | Short-circuit protected | ||
| Maximum voltage for ERROR Pin | VIN | V | |
| Maximum voltage for SENSE Pin | VOUT | V | |
| Power dissipation(5) | Internally Limited | ||
| Storage temperature, Tstg | −65 | 150 | °C |
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) If Military/Aerospace specified devices are required, please contact the TI Sales Office/Distributors for availability and specifications.
(3) If used in a dual-supply system where the regulator load is returned to a negative supply, the output must be diode-clamped to ground.
(4) The output PMOS structure contains a diode between the IN and OUT pins. This diode is normally reverse biased. This diode will get forward biased if the voltage at the output terminal is forced to be higher than the voltage at the input terminal. This diode can typically withstand 200 mA of DC current and 1 A of peak current.
(5) Internal thermal shutdown circuitry protects the device from permanent damage.
6.2 ESD Ratings
| VALUE | UNIT | |||
|---|---|---|---|---|
| V(ESD) | Electrostatic discharge | Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) | ±2000 | V |
| Charged-device model (CDM), per JEDEC specification JESD22-C101(2) | ±500 | |||
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
6.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)| MIN | MAX | UNIT | ||
|---|---|---|---|---|
| Input supply voltage(1) | 2.5 | 7 | V | |
| Shutdown input voltage | −0.3 | 7 | V | |
| Maximum operating current (DC) | 0.8 | A | ||
| Junction temperature | −40 | 125 | °C | |
(1) The minimum operating value for VIN is equal to either [VOUT(NOM) + VDROPOUT] or 2.5 V, whichever is greater.
6.4 Thermal Information
| THERMAL METRIC(1) | LP3871, LP3874 | UNIT | ||
|---|---|---|---|---|
| NC (SOT-223) | KTT (DDPAK/TO-263) | |||
| 5 PINS | 5 PINS | |||
| RθJA | Junction-to-ambient thermal resistance | 65.2 | 40.3 | °C/W |
| RθJC(top) | Junction-to-case (top) thermal resistance | 47.2 | 43.4 | °C/W |
| RθJB | Junction-to-board thermal resistance | 9.9 | 23.1 | °C/W |
| ψJT | Junction-to-top characterization parameter | 3.4 | 11.5 | °C/W |
| ψJB | Junction-to-board characterization parameter | 9.7 | 22 | °C/W |
| RθJC(bot) | Junction-to-case (bottom) thermal resistance | — | 1 | °C/W |
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.
6.5 Electrical Characteristics
Unless otherwise specified: TJ = 25°C, VIN = VO(NOM) + 1 V, IL = 10 mA, COUT = 10 µF, VSD = 2 V.| PARAMETER | TEST CONDITIONS | MIN(1) | TYP(2) | MAX(1) | UNIT | |
|---|---|---|---|---|---|---|
| VOUT | Output voltage tolerance(3) | VOUT + 1 V ≤ VIN ≤ 7 V, 10 mA ≤ IL ≤ 0.8 A | –1.5% | 0% | 1.5% | |
| VOUT + 1 V ≤ VIN ≤ 7 V, 10 mA ≤ IL ≤ 0.8 A, –40°C ≤ TJ ≤ 125°C | –3% | 3% | ||||
| ΔVOL | Output voltage line regulation(3) | VOUT + 1 V ≤ VIN ≤ 7 V | 0.02% | |||
| VOUT + 1 V ≤ VIN ≤ 7 V, –40°C ≤ TJ ≤ 125°C | 0.06% | |||||
| ΔVO/ ΔIOUT | Output voltage load regulation(3) | 10 mA ≤ IL ≤ 0.8 A | 0.04% | |||
| 10 mA ≤ IL ≤ 0.8 A, –40°C ≤ TJ ≤ 125°C | 0.1% | |||||
| VIN – VOUT | Dropout voltage(4) | IL = 80 mA | 24 | 35 | mV | |
| IL = 80 mA, –40°C ≤ TJ ≤ 125°C | 40 | |||||
| IL = 0.8 A | 240 | 300 | ||||
| IL = 0.8 A, –40°C ≤ TJ ≤ 125°C | 350 | |||||
| IGND | Ground pin current in normal operation mode | IL = 150 mA | 5 | 9 | mA | |
| IL = 150 mA, –40°C ≤ TJ ≤ 125°C | 10 | |||||
| IL = 0.8 A | 6 | 14 | ||||
| IL = 0.8 A, –40°C ≤ TJ ≤ 125°C | 15 | |||||
| IGND | Ground pin current in shutdown mode | VSD ≤ 0.3 V | 0.01 | 10 | µA | |
| –40°C ≤ TJ ≤ 85°C | 50 | |||||
| IO(PK) | Peak output current | VOUT ≥ VO(NOM) – 4% | 1 | A | ||
| SHORT CIRCUIT PROTECTION | ||||||
| ISC | Short-circuit current | 2.3 | A | |||
| SHUTDOWN INPUT | ||||||
| VSDT | Shutdown threshold | Output = High | VIN | V | ||
| Output = High, –40°C ≤ TJ ≤ 125°C | 2 | |||||
| Output = Low | 0 | |||||
| Output = Low, –40°C ≤ TJ ≤ 125°C | 0.3 | |||||
| TdOFF | Turnoff delay | IL = 0.8 A | 20 | µs | ||
| TdON | Turnon delay | IL = 0.8 A | 25 | µs | ||
| ISD | SD input current | VSD = VIN | 1 | nA | ||
| ERROR FLAG | ||||||
| VT | Threshold | See(5) | 10% | |||
| See(5), –40°C ≤ TJ ≤ 125°C | 5% | 16% | ||||
| VTH | Threshold hysteresis | See(5) | 5% | |||
| See(5), –40°C ≤ TJ ≤ 125°C | 2% | 8% | ||||
| VEF(Sat) | ERROR flag saturation | Isink = 100 µA | 0.02 | V | ||
| Isink = 100 µA, –40°C ≤ TJ ≤ 125°C | 0.1 | |||||
| Td | Flag reset delay | 1 | µs | |||
| Ilk | ERROR flag pin leakage current | 1 | nA | |||
| Imax | ERROR flag pin sink current | VError = 0.5 V | 1 | mA | ||
| AC PARAMETERS | ||||||
| PSRR | Ripple rejection | VIN = VOUT + 1 V, COUT = 10 µF VOUT = 3.3 V, ƒ = 120 Hz |
73 | dB | ||
| VIN = VOUT + 0.5 V, COUT = 10 µF VOUT = 3.3 V, ƒ = 120 Hz |
57 | |||||
| ρn(l/f) | Output noise density | ƒ = 120 Hz | 0.8 | µV | ||
| en | Output noise voltage | BW = 10 Hz – 100 kHz, VOUT = 2.5 V | 150 | µVRMS | ||
| BW = 300 Hz – 300 kH, VOUT = 2.5 V | 100 | |||||
(1) Limits are specified by testing, design, or statistical correlation.
(2) Typical numbers are at 25°C and represent the most likely parametric norm.
(3) Output voltage line regulation is defined as the change in output voltage from the nominal value due to change in the input line voltage. Output voltage load regulation is defined as the change in output voltage from the nominal value due to change in load current. The line and load regulation specification contains only the typical number. However, the limits for line and load regulation are included in the output voltage tolerance specification.
(4) Dropout voltage is defined as the minimum input to output differential voltage at which the output drops 2% below the nominal value. Dropout voltage specification applies only to output voltages of 2.5 V and above. For output voltages below 2.5 V, the dropout voltage is nothing but the input to output differential, because the minimum input voltage is 2.5 V.
(5) ERROR Flag threshold and hysteresis are specified as percentage of regulated output voltage. See ERROR Flag Operation.
6.6 Typical Characteristics
Unless otherwise specified: TJ = 25°C, COUT = 10 µF, CIN = 10 µF, SD pin is tied to VIN, VOUT = 2.5 V, VIN = VO(NOM) + 1 V,IL = 10 mA.
| IL = 800 mA |
