Document
LD3985
Ultra low drop and low noise BiCMOS voltage regulators
627/
Features
• Input voltage from 2.5 V to 6 V • Stable with low ESR ceramic capacitors • Ultra low-dropout voltage (60 mV typ. at 150
mA load, 0.4 mV typ. at 1 mA load) • Very low quiescent current (85 µA typ. at no
load, 170 µA typ. at 150 mA load; max.1.5 µA in OFF mode) • Guaranteed output current up to 150 mA • Wide range of output voltages: 1.22 V; 1.8 V; 2.5 V; 2.7 V; 2.8 V; 2.9 V; 3 V; 3.3 V; 4.7 V • Fast turn-on time: typ. 200 µs [CO = 1 µF, CBYP = 10 nF and IO = 1 mA] • Logic-controlled electronic shutdown • Internal current and thermal limit • Output low noise voltage 30 µVRMS over 10 Hz to 100 kHz • SVR of 60 dB at 1 kHz, 50 dB at 10 kHz • Temperature range: - 40 °C to 125 °C
Datasheet - production data
Description
The LD3985 provides up to 150 mA, from 2.5 V to 6 V input voltage. The ultra low drop voltage, low quiescent current and low noise make it suitable for low power applications and in battery-powered systems. Regulator ground current increases slightly in dropout only, prolonging the battery life. Power supply rejection is better than 60 dB at low frequencies and rolls off at 10 kHz. High power supply rejection is maintained down to low input voltage levels common to battery operated circuits. Shutdown logic control function is available, this means that when the device is used as local regulator, it is possible to put a part of the board in standby, decreasing the total power consumption. The LD3985 is designed to work with low ESR ceramic capacitors. Typical applications are in mobile phones and similar battery-powered wireless systems.
November 2019
This is information on a product in full production.
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Contents
Contents
LD3985
1
Diagram . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3
Typical application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
6
Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
7
Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.1 SOT23-5L package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
7.2 SOT23-5L packing information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
8
Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
9
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
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Diagram
Figure 1. Schematic diagram
Diagram
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Pin configuration
2
Pin configuration
Figure 2. Pin connection (top view)
LD3985
Table 1. Pin description
Pin
Symbol
Name and function
1
VI
Input voltage of the LDO
2
GND Common ground
3
VINH
Inhibit input voltage: ON mode when VINH ≥ 1.2 V, OFF mode when VINH ≤ 0.4 V (Do not leave it floating, not internally pulled down/up)
4
BYPASS
Bypass pin: an external capacitor (usually 10 nF) has to be connected to minimize noise voltage
5
VO
Output voltage of the LDO
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Typical application
Figure 3. Typical application circuit
Typical application
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Maximum ratings
4
Maximum ratings
LD3985
Note:
Table 2. Absolute maximum ratings
Symbol
Parameter
Value
Unit
VI
DC input voltage
-0.3 to 6 (1)
V
VO
DC output voltage
-0.3 to VI+0.3
V
VINH
Inhibit input voltage
-0.3 to VI+0.3
V
IO
Output current
Internally limited
PD
Power dissipation
Internally limited
TSTG
Storage temperature range
-65 to 150
°C
TOP
Operating junction temperature range
-40 to 125
°C
1. The input pin is able to withstand non repetitive spike of 6.5 V for 200 ms.
Absolute maximum ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is not implied.
Symbol RthJC RthJA
Table 3. Thermal data Parameter Thermal resistance junction-case Thermal resistance junction-ambient
Value 81 255
Unit °C/W °C/W
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Electrical characteristics
Electrical characteristics
TJ = 25 °C, VI = VO(NOM) +0.5 V, CI = 1 µF, CBYP = 10 nF, IO = 1 mA, VINH = 1.4 V, unless otherwise specified.
Table 4. Electrical characteristics
Symbol
Parameter
Test conditions
Min.
Typ.
VI
Operating input voltage
2.5
Output voltage
IO = 1 mA
-50
VO
accuracy, VO(NOM) < 2.5 V
TJ = -40 to 125 °C
-75
Output voltage
IO = .