STMicroelectronics LD39050PUR 500 ma low quiescent current low noise voltage regulator Datasheet

LD39050xx
500 mA low quiescent current
low noise voltage regulator
Features
■
Input voltage from 1.5 to 5.5 V
■
Ultra low dropout voltage (200 mV typ. at 500
mA load)
■
Very low quiescent current (20 µA typ. at no
load, 100 µA typ. at 500 mA load, 1 µA max in
off mode)
■
Very low noise without bypass capacitor
■
Output voltage tolerance: ± 2.0 % @ 25 °C
■
500 mA guaranteed output current
■
Wide range of output voltages available on
request: 0.8 V to 4.5 V with 100 mV step and
ADJ from 0.8 V
■
Logic-controlled electronic shutdown
■
Compatible with ceramic capacitor
COUT = 1 µF
■
Internal current and thermal limit
■
Package DFN6 (3 x 3 mm)
■
Temperature range: -40 °C to 125 °C
DFN6 (3 x 3 mm)
roll off at 10 kHz. An Enable logic control function
puts the LD39050 in shut-down mode allowing a
total current consumption lower than 1 µA. The
device also includes short-circuit constant current
limiting and thermal protection. Typical
applications are mobile phones, personal digital
assistants (PDAs), cordless phones and similar
battery-powered systems.
Description
The LD39050 provides 500 mA maximum current
from an input voltage ranging from 1.5 V to 5.5 V
with a typical dropout voltage of 200 mV. Stability
is provided using ceramic capacitors. The ultra
low drop-voltage, low quiescent current and low
noise features make it suitable for low power
battery-powered applications. Power supply
rejection is 65 dB at low frequencies and starts to
Table 1.
March 2009
Device summary
Part numbers
Order codes
Output voltages
LD39050XX
LD39050PUR
ADJ from 0.8 V
LD39050XX10
LD39050PU10R
1.0 V
LD39050XX12
LD39050PU12R
1.2 V
LD39050XX25
LD39050PU25R
2.5 V
LD39050XX33
LD39050PU33R
3.3 V
Rev 1
1/24
www.st.com
24
Contents
LD39050xx
Contents
1
Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2
Pin configuration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3
Maximum ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
4
Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
5
Typical performance characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
6
Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
6.1
Power dissipation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.2
Enable function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
6.3
Power Good function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
7
Package mechanical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
8
Different output voltage versions of the LD39050xx
available on request . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
9
Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
2/24
LD39050xx
Diagrams
1
Diagrams
Figure 1.
Schematic diagram for the LD39050PU
IN
PG
Power-good
signal
IN
BandGap
reference
Current
limit
OpAmp
OUT
Thermal
protection
ADJ
EN
Internal
enable
GND
Figure 2.
Schematic diagram for the LD39050PUxx
IN
PG
Power-good
signal
IN
BandGap
reference
Current
limit
OpAmp
OUT
Thermal
protection
R1
NC
EN
R2
Internal
enable
GND
3/24
Pin configuration
LD39050xx
2
Pin configuration
Figure 3.
Pin connection (top view)
EN
VIN
EN
GND
NC
GND
ADJ
PG
VOUT
VOUT
PG
LD39050PUxx
Table 2.
VIN
LD39050PU
Pin description
Pin n°
Symbol
LD39050PUxx
EN
1
1
Enable pin logic input: Low=shutdown, High=active
GND
2
2
Common ground
PG
3
3
Power Good
VOUT
4
4
Output voltage
ADJ
5
-
Adjust pin
VIN
6
6
Input voltage of the LDO
NC
-
5
Not connected
GND
4/24
Function
LD39050PU
EXP pad
Exposed pad must be connected to GND
LD39050xx
Maximum ratings
3
Maximum ratings
Table 3.
Absolute maximum ratings
Symbol
Value
Unit
-0.3 to 7
V
DC output voltage
-0.3 to VI + 0.3 (7 V max)
V
EN
Enable pin
-0.3 to VI + 0.3 (7 V max)
V
PG
Power Good pin
-0.3 to 7
V
ADJ
Adjust pin
4
V
IOUT
Output current
Internally limited
Power dissipation
Internally limited
VIN
VOUT
PD
Parameter
DC input voltage
TSTG
Storage temperature range
- 65 to 150
°C
TOP
Operating junction temperature range
- 40 to 125
°C
Note:
Absolute maximum ratings are those values beyond which damage to the device may occur.
Functional operation under these conditions is not implied. All values are referred to GND.
Table 4.
Thermal data
Symbol
Parameter
Value
Unit
RthJA
Thermal resistance junction-ambient
55
°C/W
RthJC
Thermal resistance junction-case
10
°C/W
Table 5.
Symbol
ESD
ESD performance
Parameter
Test conditions
Value
Unit
HBM
2
kV
MM
0.3
kV
ESD protection voltage
5/24
Electrical characteristics
4
LD39050xx
Electrical characteristics
TJ = 25 °C, VIN = 1.8 V, CIN = COUT = 1 µF, IOUT = 10 mA, VEN = VIN, unless otherwise
specified.
Table 6.
Symbol
VIN
Electrical characteristics for the LD39050PU
Parameter
Operating input voltage
VADJ
VADJ accuracy
IADJ
Adjust pin current
ΔVOUT
Static line regulation
ΔVOUT
Transient line regulation (1)
ΔVOUT
Static load regulation
ΔVOUT
Transient load regulation (1)
VDROP Dropout voltage (2)
eN
SVR
Test conditions
Output noise voltage
Supply voltage rejection
VOUT = 0.8V
Min.
Typ.
1.5
816
IOUT = 10 mA, -40°C<TJ<125°C
776
800
824
mV
1
VOUT +1 V ≤ VIN ≤ 5.5 V,
IOUT = 1 mA
0.01
ΔVIN=500 mV, IOUT=10 mA, tR=5
µs
10
ΔVIN=500 mV, IOUT=10 mA, tF=5 µs
10
6/24
Short-circuit current
IOUT = 10 mA to 500 mA
%/V
0.002
IOUT = 10 mA to 500 mA, tR=5µs
40
IOUT = 10 mA to 500 mA, tF=5µs
40
IO = 500mA, VOUT fixed to 1.5V
40°C<TJ<125°C
200
10Hz to 100kHz, IOUT = 100 mA,
VOUT = 0.8 V
30
VIN = 1.8V+/-VRIPPLE
VRIPPLE = 0.25V, freq. = 1kHz
IOUT = 10 mA
65
VIN = 1.8V+/-VRIPPLE
VRIPPLE = 0.25V, freq.=10 kHz
IOUT = 100 mA
62
IOUT = 0 mA
20
%/mA
mVpp
400
mV
µVRMS
dB
50
100
µA
IOUT=0 to 500mA, 40°C<TJ<125°C
200
VIN input current in off mode:
VEN = GND(3)
0.001
Rising edge
0.92*
VOUT
Falling edge
0.8*
VOUT
RL=0
µA
mVpp
Power Good output voltage low Isink=6mA open drain output
ISC
V
800
Power Good output threshold
PG
5.5
784
IOUT = 0 to 500mA
Quiescent current
Unit
IOUT =10 mA, TJ = 25°C
IOUT= 0 mA, -40°C<TJ<125°C
IQ
Max.
1
V
0.4
600
800
V
mA
LD39050xx
Table 6.
Electrical characteristics
Electrical characteristics for the LD39050PU (continued)
Symbol
VEN
IEN
tON
TSHDN
COUT
Parameter
Test conditions
Enable input logic low
VIN=1.5 V to 5.5 V, 40°C<TJ<125°C
Enable input logic high
VIN=1.5 V to 5.5 V, 40°C<TJ<125°C
Enable pin input current
VEN= VIN
Turn on time
Min.
Typ.
Max.
Unit
0.4
V
0.9
V
0.1
(4)
100
30
Thermal shutdown
160
Hysteresis
20
nA
µs
°C
Output capacitor
Capacitance (see typical
performance characteristics for
stability)
1
22
µF
1. All transient values are guaranteed by design, not production tested
2. Dropout voltage is the input-to-output voltage difference at which the output voltage is 100 mV below its nominal value. This
specification does not apply for output voltages below 1.5 V
3. PG pin floating
4. Turn-on time is time measured between the enable input just exceeding VEN high value and the output voltage just
reaching 95% of its nominal value
7/24
Electrical characteristics
LD39050xx
TJ = 25 °C, VIN = VOUT(NOM) + 1 V, CIN = COUT = 1 µF, IOUT = 10 mA, VEN = VIN, unless
otherwise specified.
Table 7.
Symbol
VIN
VOUT
Electrical characteristics for the LD39050PUxx
Parameter
VOUT accuracy
Static line regulation
ΔVOUT
Transient line regulation (1)
ΔVOUT
Static load regulation
ΔVOUT
Transient load regulation (1)
VDROP
SVR
Max.
Unit
1.5
5.5
V
VOUT >1.5V, IOUT =10 mA,
TJ = 25°C
-2.0
2.0
VOUT >1.5 V, IOUT = 10 mA,
-40°C<TJ<125°C
-3.0
Operating input voltage
ΔVOUT
eN
Test conditions
Min.
Typ.
%
3.0
VOUT ≤ 1.5 V, IOUT = 10 mA
±20
VOUT ≤ 1.5 V, IOUT =10 mA,
-40°C<TJ<125°C
±30
VOUT +1 V ≤ VIN ≤ 5.5 V,
IOUT = 1 mA
0.01
ΔVIN=500 mV, IOUT=10 mA, tR=5 µs
10
ΔVIN=500 mV, IOUT=10 mA, tF=5 µs
10
IOUT = 10 mA to 500 mA
0.002
40
IOUT = 10 mA to 500 mA, tF=5µs
40
Dropout voltage (2)
IOUT = 500mA, VOUT > 1.5 V
-40°C<TJ<125°C
200
Output noise voltage
10Hz to 100kHz, IO = 100 mA,
30
VIN = VOUT(NOM)+0.5V+/-VRIPPLE
VRIPPLE = 0.1V, freq. = 1kHz
IOUT = 10 mA
65
VIN = VOUT(NOM)+0.5V+/-VRIPPLE
VRIPPLE = 0.1V, freq.=10 kHz
IOUT = 100 mA
62
IOUT = 0 mA
20
Quiescent current
0.001
Rising edge
0.92*
VOUT
Falling edge
0.8*
VOUT
8/24
Short-circuit current
RL=0
µA
200
Power Good output threshold
ISC
µVRMS
100
VIN input current in off mode:
VEN = GND (3)
Isink=6mA open drain output
mV
50
IOUT = 0 to 500mA
Power Good output voltage
low
400
dB
IOUT = 0 to 500mA -40°C<TJ<125°C
PG
%/mA
mVpp
IOUT = 0 mA, -40°C<TJ<125°C
IQ
%/V
mVpp
IOUT = 10 mA to 500 mA, tR=5µs
Supply voltage rejection
VOUT = 1.5V
mV
1
V
0.4
600
800
V
mA
LD39050xx
Table 7.
Electrical characteristics
Electrical characteristics for the LD39050PUxx (continued)
Symbol
VEN
IEN
tON
TSHDN
COUT
Parameter
Test conditions
Enable input logic low
VIN=1.5 V to 5.5 V, -40°C<TJ<125°C
Enable input logic high
VIN=1.5 V to 5.5 V, -40°C<TJ<125°C
Enable pin input current
VEN = VIN
Turn on time
Min.
Typ.
Max.
Unit
0.4
V
0.9
V
0.1
(4)
100
30
Thermal shutdown
160
Hysteresis
20
nA
µs
°C
Output capacitor
Capacitance (see typical
performance characteristics for
stability)
1
22
µF
1. All transient values are guaranteed by design, not production tested
2. Dropout voltage is the input-to-output voltage difference at which the output voltage is 100 mV below its nominal value. This
specification does not apply for output voltages below 1.5 V
3. PG pin floating
4. Turn-on time is time measured between the enable input just exceeding VEN high value and the output voltage just reaching
95 % of its nominal value
9/24
Typical performance characteristics
LD39050xx
Typical performance characteristics
Figure 4.
VADJ accuracy
Figure 5.
0.85
0.84
0.83
2.55
2.54
2.53
0.82
0.81
0.8
0.79
0.78
2.52
2.51
2.5
2.49
2.48
VOUT [V]
VADJ [V]
5
0.77
0.76
0.75
2.47
2.46
2.45
VIN = 1.8 V IOUT = 10 mA VEN = VIN
-50
-25
0
25
50
75
VOUT accuracy
100
125
VIN = 3.5 V IOUT = 10 mA VEN = VIN
-50
150
-25
0
25
50
Dropout voltage vs. temperature
Figure 7.
350
350
300
300
250
250
Dropout [mV]
Dropout [mV]
Figure 6.
200
150
100
0
25
50
200
150
100
CIN = COUT = 1 µF
75
100
125
0
-50
150
-25
0
25
50
Dropout [V]
ISC [A]
VEN to VIN, CIN = COUT = 1 µF
100
200
300
IOUT [mA]
10/24
100
125
150
400
500
600
Short-circuit current vs. dropout
voltage
1.2
1.1
1
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
0
125 °C
85 °C
55 °C
25 °C
0 °C
-25 °C
-40 °C
VIN from 0 to 5.5 V, VEN = VIN, CIN = 1 µF, COUT = 1 µF
0
0
75
T [°C]
Dropout voltage vs. output current Figure 9.
0.3
0.275
0.25
0.225
0.2
0.175
0.15
0.125
0.1
0.075
0.05
0.025
0
150
Dropout voltage vs. temperature
T [°C]
Figure 8.
125
50
CIN = COUT = 1 µF
-25
100
VEN to VIN, IOUT = 500 mA, VOUT = 2.5 V
VEN to VIN, IOUT = 500 mA, VOUT @ 1.5 V
50
0
-50
75
T [°C]
T [°C]
1
2
3
VDROP [V]
4
5
6
LD39050xx
Typical performance characteristics
Figure 10. Output voltage vs. input voltage
Figure 11. Quiescent current vs. temperature
0.9
0.7
125°C
0.6
85°C
0.5
55°C
0.4
25°C
0.3
0°C
Iq [µA]
VOUT [V]
0.8
- 25°C
0.2
0.1
- 40°C
VEN = VIN, CIN = COUT = 1 µF; IOUT = 500 mA
0
0
0.5
1
1.5
2
2.5
3
3.5
4
4.5
5
100
90
80
70
60
50
40
30
20
10
0
-50
No load
IOUT = 0.5 A
VIN = 1.8 V, VEN to VIN, CIN = 1 µF COUT = 1 µF, VOUT = 0.8 V
-25
0
25
5.5
50
75
100
125
150
T [°C]
VIN [V]
Figure 12. Quiescent current vs. temperature
Figure 13. Quiescent current in off mode vs.
temperature
VIN = 3.5 V, VOUT = 2.5 V, VEN = GND, CIN = COUT = 1 µF
0.5
0.4
Iq [µA]
Iq [µA]
0.6
100
90
80
70
60
50
40
30
20
10
0
-50
No load
VIN = 3.5 V, VEN to VIN, CIN = COUT = 1 µF, VOUT = 2.5 V
IOUT = 0.5 A
0.3
0.2
0.1
-25
0
25
50
75
100
125
0
150
-50
T [°C]
-25
0
25
50
75
100
125
150
T [°C]
Figure 14. Load regulation
Figure 15. Line regulation
0.04
0.04
IOUT = 100 mA
0.02
0.01
0
-0.01
0.01
0
-0.01
-0.02
-0.02
-0.03
-0.03
-0.04
-50
IOUT = 1 mA
0.03
0.02
Line [%/V]
Load [%/mA]
0.03
-0.04
-50
VIN = 1.8 V, IOUT = from 10 mA to 500 mA, VOUT = 0.8 V, VEN = VIN
-25
0
25
50
75
100
125
150
VIN = from 1.8 V to 5.5 V VEN = VIN VOUT = 0.8 V
-25
0
25
50
75
100
125
150
T [°C]
T [°C]
11/24
Typical performance characteristics
LD39050xx
Figure 16. Line regulation
Figure 17. Supply voltage rejection vs.
temperature
0.04
100
90
80
IOUT = 1 mA
0.03
IOUT = 100 mA
SVR [dB]
Line [%/V]
0.02
0.01
0
-0.01
-0.02
-0.03
-0.04
-50
VIN = from 3.5 V to 5.5 V VOUT = 2.5 V VEN = VIN
-25
0
25
50
T [°C]
75
100
125
150
SVR [dB]
SVR [dB]
VIN from 1.7 V to 1.9 V, VOUT = 0.8 V, VEN to VIN, IOUT = 100 mA, freq. = 10 kHz
CIN = COUT = 1 µF
-25
0
25
50
CIN = COUT = 1 µF
-25
0
25
75
100
125
150
100
90
80
70
60
50
40
30
20
10
0
-50
SVR [dB]
SVR [dB]
CIN = COUT = 1 µF
25
50
T [°C]
12/24
125
150
CIN = COUT = 1 µF
-25
0
25
50
75
100
125
150
Figure 21. Supply voltage rejection vs.
frequency
VIN from 2.9 V to 3.1 V, VOUT = 2.5 V, VEN to VIN, IOUT = 100 mA, freq. = 10 kHz
0
100
T [°C]
Figure 20. Supply voltage rejection vs.
temperature
-25
75
VIN from 2.9 V to 3.1 V, VOUT = 2.5 V, VEN to VIN, IOUT = 10 mA, freq. = 1 kHz
T [°C]
100
90
80
70
60
50
40
30
20
10
0
-50
50
Figure 19. Supply voltage rejection vs.
temperature
100
90
80
-50
VIN from 1.7 V to 1.9 V, VOUT = 0.8 V, VEN to VIN, IOUT = 10 mA, freq. = 1 kHz
T [°C]
Figure 18. Supply voltage rejection vs.
temperature
70
60
50
40
30
20
10
0
70
60
50
40
30
20
10
0
-50
75
100
125
150
100
90
80
70
60
50
40
30
20
10
0
IOUT = 10 mA
IOUT = 100 mA
VIN from 1.7 V to 1.9 V, VEN to VIN, VOUT = 0.8 V, CIN = COUT = 1 µF
0
10
20
30
40
50
60
Freq [kHz]
70
80
90
100
LD39050xx
Typical performance characteristics
Figure 22. Supply voltage rejection vs.
frequency
AP - IOUT = 100mA
100
90
5.0
IOUT = 10 mA
80
70
60
50
40
30
20
10
0
VIN from 2.9 V to 3.1 V, VEN to VIN, VOUT = 2.5 V, CIN = COUT = 1 µF
0
10
20
30
40
50 60
Freq [kHz]
70
80
90
AP - IOUT = 10mA
4.5
4.0
IOUT = 100 mA
eN [uV/SQRT(Hz)]
SVR [dB]
Figure 23. Noise output voltage vs. frequency
AP - IOUT = 1m
AP - IOUT = 0A
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0.0
1.E+01
100
1.E+02
1.E+03
f [Hz]
1.E+04
1.E+05
VIN = 1.8 V, VOUT = 0.8 V, VEN = 1 V, CIN = COUT = 1 µF,
TA = 25 °C
Figure 24. Enable voltage vs. temperature
1
1
0.9
0.8
High
0.9
0.8
Low
0.7
0.6
VEN [V]
VEN [V]
Figure 25. Enable voltage vs. temperature
0.5
0.4
High
Low
0.7
0.6
0.5
0.4
0.3
0.2
0.3
0.2
0.1
0
0.1
0
VIN = 3.5 V IOUT = 10 mA, VOUT = 2.5 V, CIN = COUT = 1 µF
-50
-25
0
25
50
75
100
125
150
-50
T [°C]
Figure 26. Load transient
-25
0
25
50
75
100
125
150
T [°C]
Figure 27. Load transient
VOUT
VOUT
IOUT
IOUT
VEN = VIN=1.8 V, IOUT = from10 mA to 0.5 A, CIN = COUT = 1
µF, VOUT = 0.8 V
VIN = 5.5 V IOUT = 10 mA VOUT = 2.5 V, CIN = COUT = 1 µF
VEN = VIN = 3.5V, IOUT from 10 mA to 0.5 A, VOUT = 2.5 V,
CIN = COUT = 1 µF
13/24
Typical performance characteristics
Figure 28. Load transient
LD39050xx
Figure 29. Line transient
VOUT
VOUT
VIN
IOUT
VEN = VIN = 3.5 V, IOUT from 100 mA to 0.5 A, VOUT = 2.5 V,
CIN = COUT = 1 µF
VEN = VIN from 4.3 V to 4.8 V, IOUT = 10 mA, COUT = 1 µF,
CIN = NO
Figure 30. Startup transient
Figure 31. Enable transient
VOUT
VIN
VOUT
VEN
VEN = VIN = from 0 V to 5.5 V, IOUT=10 mA, CIN = COUT = 1
µF, VOUT = 2.5 V
VEN from 0 V to 2 V, VIN = 3.5 V, VOUT = 2.5 V, IOUT = 10
mA, CIN = COUT = 1µF
Figure 32. ESR required for stability with
ceramic capacitors
Figure 33. ESR required for stability with
ceramic capacitors
1.5
ESR @ 100 kHz [Ω]
1
0.75
STABLE ZONE
0.5
ESR @ 100 kHz [Ω]
1.5
UNSTABLE ZONE
1.25
UNSTABLE ZONE
1.25
1
0.75
0.5
STABLE ZONE
0.25
0.25
0
0
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22
COUT [µF] (nominal value)
VIN = VEN = from 1.8 V to 5.5 V, IOUT = from 1 mA to 500
mA, VOUT = 0.8 V, CIN = 1 µF
14/24
1
2
3
4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20 21 22
COUT [µF] (nominal value)
VIN = VEN = from 3.5 V to 5.5 V, IOUT = from 1 mA to 500
mA, VOUT = 2.5 V, CIN = 1 µF
LD39050xx
6
Application information
Application information
The LD39050 is an ultra low dropout linear regulator. It provides up to 500 mA with a low
200 mV dropout. The input voltage range is from 1.5 V to 5.5 V. The device is available in
fixed and adjustable output versions.
The regulator is equipped with internal protection circuitry, such as short-circuit current
limiting and thermal protection.
The regulator is designed to be stable with ceramic capacitors on the input and the output.
The expected values of the input and output ceramic capacitors are from 1 µF to 22 µF with
1 µF typical. The input capacitor must be connected within 0.5 inches of the VIN terminal.
The output capacitor must also be connected within 0.5 inches of output pin. There is no
upper limit to the value of the input capacitor.
Figure 34 and Figure 35 illustrate the typical application schematics:
Figure 34. Application schematic for fixed version
VIN
6
1
CIN
VIN
3
PG
LD39050PUxx
VOUT
EN
VOUT
4
OFF ON
1µF
GND
COUT
5
NC
1µF
2
Figure 35. Application schematic for adjustable version
VIN
I
CIN
1µF
6
VIN
1
EN
PG
LD39050PU
VOUT
3
OFF ON
GND
2
ADJ
VOUT
4
5
R1
COUT
1µF
R2
15/24
Application information
LD39050xx
For the adjustable version, the output voltage can be adjusted from 0.8 V up to the input
voltage minus the voltage drop across the PMOS (dropout voltage), by connecting a resistor
divider between the ADJ pin and the output, thus allowing remote voltage sensing.
The resistor divider should be selected using the following equation:
VOUT = VADJ (1 + R1 / R2) with VADJ = 0.8 V (typ.)
It is recommended to use resistors with values in the range of 10 kΩ to 50 kΩ. Lower values
can also be suitable, but will increase current consumption.
6.1
Power dissipation
An internal thermal feedback loop disables the output voltage if the die temperature rises to
approximately 160 °C. This feature protects the device from excessive temperature and
allows the user to push the limits of the power handling capability of a given circuit board
without risk of damaging the device.
It is very important to use a good PC board layout to maximize power dissipation. The
thermal path for the heat generated by the device is from the die to the copper lead frame
through the package leads and exposed pad to the PC board copper. The PC board copper
acts as a heat sink. The footprint copper pads should be as wide as possible to spread and
dissipate the heat to the surrounding ambient. Feed-through vias to inner or backside
copper layers are also useful in improving the overall thermal performance of the device.
The power dissipation of the device depends on the input voltage, output voltage and output
current, and is given by:
PD = (VIN -VOUT) IOUT
The junction temperature of the device is:
TJ_MAX = TA + RthJA x PD
where:
TJ_MAX is the maximum junction of the die,125 °C;
TA is the ambient temperature;
RthJA is the thermal resistance junction-to-ambient.
6.2
Enable function
The LD39050 features an enable function. When the EN voltage is higher than 2 V the
device is ON, and if it is lower than 0.8 V the device is OFF. In shutdown mode, consumption
is lower than 1 µA.
The EN pin does not have an internal pull-up, which means that it cannot be left floating if it
is not used.
6.3
Power Good function
Most applications require a flag showing that the output voltage is in the correct range.
The Power Good threshold depends on the adjust voltage. When the adjust is higher than
0.92*VADJ, the Power Good (PG) pin goes to high impedance. If the adjust is below
16/24
LD39050xx
Application information
0.80*VADJ the PG pin goes to low impedance. If the device is functioning well, the Power
Good pin is at high impedance. If the output voltage is fixed using an external or internal
resistor divider, the Power Good threshold is 0.92*VOUT.
The use of the Power Good function requires an external pull-up resistor, which must be
connected between the PG pin and VIN or VOUT. The typical current capability of the PG pin
is up to 6 mA. The use of a pull-up resistor for PG in the range of 100 kΩ to 1 MΩ is
recommended. If the Power Good function is not used, the PG pin must remain floating.
17/24
Package mechanical data
7
LD39050xx
Package mechanical data
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com. ECOPACK
is an ST trademark.
18/24
LD39050xx
Package mechanical data
DFN6 (3x3 mm) mechanical data
mm.
inch.
Dim.
Min.
Typ.
Max.
Min.
Typ.
Max.
A
0.80
0.90
1.00
0.031
0.035
0.039
A1
0
0.02
0.05
0
0.001
0.002
A3
0.20
0.008
b
0.23
0.30
0.38
0.009
0.012
0.015
D
2.90
3.00
3.10
0.114
0.118
0.122
D2
2.23
2.38
2.48
0.088
0.094
0.098
E
2.90
3.00
3.10
0.114
0.118
0.122
E2
1.50
1.65
1.75
0.059
0.065
0.069
e
L
0.95
0.30
0.40
0.037
0.50
0.012
0.016
0.020
7946637A
19/24
Package mechanical data
LD39050xx
Tape & reel QFNxx/DFNxx (3x3) mechanical data
mm.
inch.
Dim.
Min.
Typ.
A
Min.
Typ.
330
13.2
Max.
12.992
C
12.8
D
20.2
0.795
N
60
2.362
T
20/24
Max.
0.504
0.519
18.4
0.724
Ao
3.3
0.130
Bo
3.3
0.130
Ko
1.1
0.043
Po
4
0.157
P
8
0.315
LD39050xx
Package mechanical data
Figure 36. DFN6 (3x3) footprint recommended data
21/24
Different output voltage versions of the LD39050xx available on request
LD39050xx
8
Different output voltage versions of the LD39050xx
available on request
Table 8.
Options available on request
22/24
Order codes
Output voltages
LD39050PU105R
1.05 V
LD39050PU15R
1.5 V
LD39050PU18R
1.8 V
LD39050xx
Revision history
9
Revision history
Table 9.
Document revision history
Date
Revision
11-Mar-2009
1
Changes
Initial release.
23/24
LD39050xx
Please Read Carefully:
Information in this document is provided solely in connection with ST products. STMicroelectronics NV and its subsidiaries (“ST”) reserve the
right to make changes, corrections, modifications or improvements, to this document, and the products and services described herein at any
time, without notice.
All ST products are sold pursuant to ST’s terms and conditions of sale.
Purchasers are solely responsible for the choice, selection and use of the ST products and services described herein, and ST assumes no
liability whatsoever relating to the choice, selection or use of the ST products and services described herein.
No license, express or implied, by estoppel or otherwise, to any intellectual property rights is granted under this document. If any part of this
document refers to any third party products or services it shall not be deemed a license grant by ST for the use of such third party products
or services, or any intellectual property contained therein or considered as a warranty covering the use in any manner whatsoever of such
third party products or services or any intellectual property contained therein.
UNLESS OTHERWISE SET FORTH IN ST’S TERMS AND CONDITIONS OF SALE ST DISCLAIMS ANY EXPRESS OR IMPLIED
WARRANTY WITH RESPECT TO THE USE AND/OR SALE OF ST PRODUCTS INCLUDING WITHOUT LIMITATION IMPLIED
WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE (AND THEIR EQUIVALENTS UNDER THE LAWS
OF ANY JURISDICTION), OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY RIGHT.
UNLESS EXPRESSLY APPROVED IN WRITING BY AN AUTHORIZED ST REPRESENTATIVE, ST PRODUCTS ARE NOT
RECOMMENDED, AUTHORIZED OR WARRANTED FOR USE IN MILITARY, AIR CRAFT, SPACE, LIFE SAVING, OR LIFE SUSTAINING
APPLICATIONS, NOR IN PRODUCTS OR SYSTEMS WHERE FAILURE OR MALFUNCTION MAY RESULT IN PERSONAL INJURY,
DEATH, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE. ST PRODUCTS WHICH ARE NOT SPECIFIED AS "AUTOMOTIVE
GRADE" MAY ONLY BE USED IN AUTOMOTIVE APPLICATIONS AT USER’S OWN RISK.
Resale of ST products with provisions different from the statements and/or technical features set forth in this document shall immediately void
any warranty granted by ST for the ST product or service described herein and shall not create or extend in any manner whatsoever, any
liability of ST.
ST and the ST logo are trademarks or registered trademarks of ST in various countries.
Information in this document supersedes and replaces all information previously supplied.
The ST logo is a registered trademark of STMicroelectronics. All other names are the property of their respective owners.
© 2009 STMicroelectronics - All rights reserved
STMicroelectronics group of companies
Australia - Belgium - Brazil - Canada - China - Czech Republic - Finland - France - Germany - Hong Kong - India - Israel - Italy - Japan Malaysia - Malta - Morocco - Singapore - Spain - Sweden - Switzerland - United Kingdom - United States of America
www.st.com
24/24