STMICROELECTRONICS L4955

L4955

5A ULDO LINEAR REGULATORS FAMILY
UP TO 5A OUTPUT CURRENT
±2% PRECISE OUTPUT VOLTAGES
FAST TRANSIENT RESPONSE
0.75V TYP. DROP OUT VOLTAGE AT 5A
OPERATING INPUT VOLTAGE FROM 4.5V
ADJUSTABLE VERSION:
• VO = 1.26V
• INHIBIT (IQ = 120µA TYP.)
• POWER GOOD
• PROGRAMMABLE CURRENT LIMIT
• HEPTAWATT PACKAGE
FIXED VERSION:
• 3.3V, 5.1V OUTPUTS
• VERSAWATT PACKAGE
VERY LOW QUIESCENT CURRENT
SHORT CIRCUIT PROTECTION (Foldback
function)
THERMAL SHUTDOWN
APPLICATIONS
PENTIUM AND POWER PC SUPPLIES
POST REGULATOR FOR SMPS
LOW COST SOLUTION FOR 5V TO 3.3V
CONVERSION
LOW COST BATTERY CHARGER
CONSTANT CURRENT REGULATOR
SUITABLE
FOR
APPLICATION WITH
STANDBY FEATURE
DESCRIPTION
The L4955 is a family of monolithic ultra very low
drop linear regulators designed to supply the
most recent microprocessors.
MULTIPOWER BCD TECHNOLOGY
HEPTAWATT
VERSAWATT
(TO-220)
OUTPUT
VOLTAGE
ORDERING
NUMBERS
L4955
PACKAGE
1.26V ADJ
HEPTAWATT
L4955V3.3
3.3V
VERSAWATT
L4955V5.1
5.1V
VERSAWATT
The dropout voltage is only 0.75V (Typ.) at 5A, directly dependent on the output current conditions.
Realized in BCDII technology, it has on board a
charge pump to properly drive an N-channel
power mos Transistor with 150mΩ of RDSON.
It operates from a 4.5V minimum supply, with a
very low quiescent current irrespective of the
load; a minimum of 22µF output capacitor is required for stability.
The on-chip trimming techniques improve the precision of the available output voltages to ±2%.
Ancillary functions like power good, inhibit with
low power consumption, programmable output
voltage and current limiting make the flexible
heptawatt version usable in applications where
power management, stand-by, features, post
regulation and adjustable current generators for
battery chargers are important.
TYPICAL APPLICATIONS
IN
VIN
1
INH
PG
3
6
7
OUT
L4955
2
C1
CL
4
VOUT
R1
5
GND
ADJ
C2
R2
IN
VIN
C1
1
L4955VXXX
3
OUT
2
VOUT
C2
GND
D97IN590
D97IN589
February 1999
1/14
L4955
ABSOLUTE MAXIMUM RATINGS
Symbol
Parameter
Value
Supply Input Voltage
VIN
ADJ and CL pins
PG and INH pins
PTOT
Power Dissipation @ Tamb = 50°C
Power Dissipation @ Tcase = 90°C
Tst, Ti
Storage Temperature
Unit
24
V
-0.3 to 4
0 to VIN
V
V
2
15
W
W
-40 to +150
°C
PIN CONNECTIONS (Top views)
7
OUT
6
PG
5
ADJ
4
GND
3
INH
2
CL
1
IN
3
OUT
GND
1
IN
D96IN369
tab connected to pin 4
D96IN367
VERSAWATT
(TO220)
HEPTAWATT
BLOCK DIAGRAM
VIN
IN
1(1)
10µF
VREF=
1.26V
FIXED
C.L.
+
PRE
REGULATOR
-
CHARGE
PUMP
FOLDBACK
PROGRAM.
C.L.
OUT
7(3)
3
R1
ADJ
VREF
INHIBIT
ACTIVE HIGH
5
+
0.9V REF
-
4(2)
2
PIN x = HEPTAWATT
PIN (x) = VERSAWATT
RCL
(1/4W, 1%)
-
1.26V
2/14
THERMAL
SHUTDOWN
+
INH
POWER
DMOS
150mΩ
BUFFER
E/A
CL
GND
6
PG
D96IN366
R2
VOUT
22µF
L4955
PIN FUNCTIONS
HW
VW
Name
Function
1
1
IN
Unregulated input voltage; this pin must be bypassed with a capacitor larger than 10µF.
2
–
CL
A resistor connected between this pin and ground sets the programmable current limiting
value. When the programmable current limiting is not used the pin must be connected to GND.
3
–
INH
TTL-CMOS input. A logic high level on this input disables the device. An internal pull-down
insures full functionally even if the pin is open.
4
2
GND
Ground.
5
–
ADJ
The output is connected directly to this terminal for 1.26V operation; it is connected to the
output through a resistive divider for higher voltages.
6
–
PG
Open drain output, this signal is low when the output voltage is lower than 90%, otherwise is high.
7
3
OUT
Regulated output voltage. A minimum bypass capacitor of 22µF is required to insure stability.
THERMAL DATA (HEPTAWATT & VERSAWATT packages)
Symbol
Parameter
Value
Unit
Rth j-case
Thermal Resistance Junction-case
Max.
2.5
°C/W
Rth j-amb
Thermal Resistance Junction-ambient
Max.
50
°C/W
Thermal Shutdown
Typ.
150
°C
Thermal Hysteresis
Typ.
20
°C
L4955 - ELECTRICAL CHARACTERISTICS (Tj = 25°C, Vin = 12V, unless otherwise specified).
• = Specifications referred to TJ from 0°C to +125°C.
Symbol
Parameter
VIN
Operating Supply Voltage
VO
Output Voltage (1)
∆V O
Line regulation
∆V O
VO
Test Condition
0.1A < IO < 5A; 4.5V < VIN <12V
•
Max.
Unit
22
V
V
1.235
1.26
1.285
1.222
1.26
1.298
V
4.5V < VIN <22V; IO = 10mA
2
10
mV
Load regulation (1)
0.1A < IO < 5A
2
10
mV
Dropout Voltage
IO = 5A
VIN ≥ 4.5V
(1)
•
•
•
•
•
•
IO = 2A
IQ
Typ.
4.5
4.5V < VIN < 12V; 0.1A < IO < 5A
IO
Min.
Current Limiting
Short Circuit Current
VO = 0V
Programmable Current
Limiting
Rlim = 13kΩ
Rlim = 47kΩ
Quiescent Current
0.1A < IO < 5A
Stand By Current
INH = 5V
Inhibit Threshold
Rising Edge
5.1
1.1
V
1.1
1.5
V
0.55
0.75
V
6.3
7.5
A
3
0.85
3.45
1.00
A
A
2
2.7
3
4
mA
mA
120
200
1.26
1.42
µA
V
60
µA
1.8
2.55
0.70
CL = 0
C L = 13k
•
0.75
1.1
Inhibit Hysteresis
A
0.2
Inhibit Bias Sink Current
INH = 5V or 0.8V
Power Good Threshold
Rising Edge
Power Good Hysteresis
Power Good Saturation
IPG = 4mA
Ripple Rejection
f = 120Hz, IO = 5A
VIN = 6V ∆VIN = 2VPP
20
V
V
0.9 x VO
•
•
0.2
0.1
60
75
V
0.4
V
dB
(1) Output voltage connected to ADJ.
3/14
L4955
L4955V3.3 - ELECTRICAL CHARACTERISTICS (Tj = 25°C, Vin = 5V, unless otherwise specified)
• = Specifications referred to TJ from 0°C to +125°C.
Symbol
Parameter
VIN
Operating Input Voltage
VO
Output Voltage
Test Condition
Min.
Typ.
4.5
4.75V < VIN < 12V; 0.1A < IO < 5A
4.75V < VIN < 12V; 0.1A < IO < 5A
•
Max.
Unit
22
V
3.234
3.300
3.366
V
3.201
3.300
3.399
V
∆V O
Line regulation
4.5V < VIN <12V; IO = 10mA
2
10
mV
∆V O
Load regulation
0.1A < IO < 5A
3
15
mV
IO
Current Limiting
6.3
7.5
A
IQ
•
•
Short Circuit Current
VO = 0V
Quiescent Current
0.1A < IO < 5A
Ripple Rejection
f = 120Hz, IO = 5A
VIN = 6V ∆VIN = 2VPP
5.1
1.8
2
57
A
3
70
mA
dB
L4955V5.1 - ELECTRICAL CHARACTERISTICS (Tj = 25°C, Vin = 8V, unless otherwise specified)
• = Specifications referred to TJ from 0°C to +125°C.
Symbol
Parameter
VIN
Operating Input Voltage
VO
Output Voltage
Test Condition
Drop-out Voltage
6.75V < VIN < 15V; 0.1A < IO < 5A
•
Max.
Unit
22
V
5.000
5.100
5.200
V
4.950
5.100
5.250
V
0.75
1.1
V
1.1
1.5
V
0.55
0.75
V
IO = 5A
IO = 2A
•
•
∆V O
Line regulation
6.5V < VIN <15V; IO = 10mA
2
10
mV
∆V O
Load regulation
0.1A < IO < 5A
5
20
mV
IO
Current Limiting
6.3
7.5
A
IQ
4/14
Typ.
VO+VD
6.75V < VIN < 15V; 0.1A < IO < 5A
VD
Min.
Short Circuit Current
VO = 0V
Quiescent Current
0.1A < IO < 5A
Ripple Rejection
f = 120Hz, IO = 5A
VIN = 8V ∆VIN = 2VPP
•
•
5.1
1.8
2
55
65
A
3
mA
dB
L4955
L4955
Figure 1: L4955 DC Operating Area
Figure 2: Output Voltage Stability vs. Junction
Temperature
O u tput C ur rent [A ]
8
Vo u t [V ]
7
1 .2 8
V in > 4.5V
T j = 125°C
C urr ent Lim itation
6
1 .2 7
5
1 .2 6 5
R dson
lim it
4
Pow er D is sipation Lim it
1 .2 6
T c = 25°C
P dm ax = 40W
3
2
1 .2 5 5
1 .2 5
D C O perating A re a
1
0
V in = 1 2 V
Io u t= 1 0 m A
1 .2 7 5
1 .2 4 5
T c = 70°C
P dm ax = 22W
0
2.5
5
7.5
10 12.5 15
(V in - Vou t) [V ]
17.5
20
22.5
40
1 20
160
5
[m V ]
5
4 .5
4
4 .5V < V in< 2 2V
Iou t= 1 0 m A
3
2 .5
2
1 .5
1
V in = 1 2 V
T j = 25 ° C
3
D eviation
4
3 .5
( P u ls e d t e c h n iq u e h a s b e e n u s e d )
2
Vo u t = V A D J
1
0
-1
-2
-3
0 .5
-4
0
-4 0 -2 0
0
20 40 60 80 100 120 140 160
-5
0
1
2
T j [°C ]
3
4
5
Io u t [A ]
Figure 5: Dropout Voltage
M in im u m V in - Vo u t Vo lta g e [V ]
80
Figure 4: Load Regulation
O utput Voltage
[m V
Deviation
Voltage
0
T j [°C ]
Figure 3: Line Regulation vs. Junction
Temperature
Output
1 .2 4
-40
Figure 6: Maximum OutputCurrent vs. Junction
Temperaturewith internalcurrent limiting
1 .2 5
O utput C urrent [A]
10
9
1
8
T j = 1 2 5 °C
7
0 .7 5
6
T j = 2 5 °C
5
0 .5
4
T j = -4 0 °C
3
(Vin-Vout) > 2V
pin 2 = G ND
2
0 .2 5
1
P u l s e d t e c h n iq u e h a s b e e n u s e d
0
0
1
2
3
Io u t [A ]
4
5
6
0
-40 -20
0
20
40
60 80 100 120 140 160
Tj [°C]
*P ulsed tecnique ha s been used
5/14
L4955
L4955
Figure 7: Short-circuit Current vs. Junction
Temperature with Programmable
Current Limiting
Figure 8: Quiescent Current vs. Temperature
(CL = 0V)
S h o r t- c ir c uit C u r r e nt [A ]
3 .5
Iq [m A ]
2 .6
2 .4
3
2 .2
R lim = 1 3 kΩ
2 .5
2
1 .8
2
1 .6
R lim = 1 9 k Ω
1 .5
1 .4
1 .2
1
1
0 .5
0 .8
R lim = 4 7 k Ω
0
-40 -20
0
20
4 0 60 80
T j [ °C ]
V in = 1 2 V
Io u t =1 0 m A t o 5 A
0 .6
10 0 12 0 1 40 160
0 .4
-4 0 - 2 0
0
20
40
* P u ls ed te c ni q u e h as b e e n u s e d
6 0 8 0 1 00 1 20 1 4 0 1 6 0
T j [° C ]
Figure 9: Quiescent Current vs. Supply voltage
(CL = 0V)
Figure 10: Quiescent Current vs. Supply Voltage
with Programmable Current Limiting
I q [m A ]
5
Iq [mA]
5
4 .5
4.5
4
4
Tj = 25°C
Io = 1 0 m A t o 5 A
3 .5
3.5
3
3
2 .5
2.5
T j= - 4 0 ° C
2
1 .5
2
Rlim = 47kΩ
1.5
T j= 2 5 ° C
T j= 1 2 5 ° C
1
Rli m = 13kΩ
1
0.5
0 .5
0
0
0
5
10
15
V in [ V ]
20
25
Figure 11: Stand-by Current vs. Supply Voltage
with INH = LOGIC HIGH
Iq [u A ]
400
0
5
10
15
20
25
Vin [V]
Figure 12: Ripple Rejection vs. Frequency
R i p p le R e je c tio n [d B ]
1 00
T j= 2 5 ° C
350
90
V r ip p le = 3 V p - p
80
300
V r ip p le = 0 . 5 V p - p
70
250
60
200
50
150
40
100
30
C in = 2 2 u F
C o u t = 2 2uF
V o ut = 1.26 V
V in m in = 4 . 5 V
Io u t = 5 A
20
50
10
0
0
5
10
15
V in [V ]
6/14
20
25
0
10
100
1k
F r e q u e n c y [H z ]
10k
1 00 k
L4955
L4955
Figure 13: Ripple Rejection vs. Output Current
Figure 14: Power Good Function
R i p p le R e je c t io n [d B ]
100
90
VADJ
VOUT=VADJ (R1+R2)/R2
F r ip p le = 1 2 0 H z
V r ip p le = 3 V p - p
80
0.9 VADJ
hyst = 200mV
F r ip p l e = 1 k H z
V r ip p le = 0 . 5 V p - p
70
60
t
F r ip p l e = 1 0 k H z
V r ip p le = 0 . 5 V p - p
50
PG
40
30
F r ip p l e = 5 0 k H z
V r ip p le = 0 . 5 V p -p
C in = 2 2 u F
C o u t= 2 2 u F
V o u t= 1 .2 6 V
V in m i n = 4 . 5 V
20
10
Low
High
Low
t
0
D96IN364B
0
1
2
3
I o u t [A ]
4
5
Figure 15: Inhibit Function
VINH
Vref = 1.26V
hyst = 200mV
t
regulator
ON
regulator
OFF
regulator
ON
D96IN365A
t
7/14
L4955
LINE TRANSIENT RESPONSE
Figure 16.
Figure 17.
Figure 18.
Test condition: VIN = 12V; ∆VIN = 1V; VO = 3.3V; IO = 200mA; CIN = 10µF (electrolytic capacitor);
Cout = 22µF (electrolytic capacitor); dV/dt = 0.1 V/µs; TJ = 25°C
8/14
L4955
LOAD TRANSIENT RESPONSE
Figure 19.
Figure 20.
Figure 21.
Test condition: VIN = 5V, VOUT = 3.3V; Load Transient from 0.5A to 5A;
dIout
= 20A ⁄ µs; TJ = 25°C
dt
Figure 22: Load transient test circuit.
PG
VIN = 5V
IN
1
7
6
L4955
C1,C2
470µF/25V
Panasonic
HFQ
2
CL
4
GND
3
5
INH
OUT
ADJ
VOUT = 3.3V
R4
910
R5
560
C4 to C9
100µF/10V
AVX TPS
6 each
C10 to C15
1µF
AVX X7R
6 each
D97IN546
9/14
L4955
L4955V3.3
Figure 23: DC operating area.
Figure 24: Output Voltage Stability vs. Junction
Temperature.
O utput Current [A]
Vo ut [V ]
8
3 .4
7
V in = 5V
Iou t = 1 0mA
Vout = 3.3V
T j = 125°C
Current Lim itation
6
3 .35
Power Dissipation Lim it
5
Rdson
lim it
4
T c = 25°C
Pdm ax=40W
3 .3
3
2
3 .25
DC O perating Area
1
0
3
4.5
6
7.5
9
T c=70°C
Pdm ax=22W
10.5 12 13.5 15 16.5 18 19.5 21 22.5
3 .2
-4 0
0
40
Input Voltage [V]
80
120
1 60
4
5
T j [°C ]
Figure 25: Quiescent Current vs. Temperature.
Figure 26: Load Regulation
Iq [m A]
5
3
4
Output Voltage Deviation [mV]
2 .7 5
2 .5
2 .2 5
2
1 .7 5
1 .5
1 .2 5
1
V in= 5 V
I ou t = 10 m A to 5 A
0 .7 5
0 .5
2
1
0
-1
-2
-3
Vin=5V
Tj = 25 °C
(Pulsed tecnique has been used)
-4
0 .2 5
0
-4 0
-5
-2 0
0
20
40
60
T j [°C ]
80
1 00
120
1 40
5
3
Figure 28: MaximumOutput Current vs.Junction
Temperaturewith internalcurrent limiting
9
8
4.5 V < V in < 12 V
Io u t = 1 0 m A
7
3
6
2.5
5
2
4
1.5
3
1
2
(Vin-Vout) > 2V
pin 2 = G ND
1
0.5
10/14
2
O utput C urrent [A]
10
4
0
-40
1
Iout [A]
4.5
3.5
0
160
Figure 27: Line regulation vs. Junction Temperature.
Output Voltage Deviation [mV]
3
-2 0
0
20
40
60
80
T j [°C ]
10 0 1 20
1 40
160
0
-40 -20
0
20
40
60 80 100 120 140 160
Tj [°C]
*P ulsed tecnique ha s been used
L4955
L4955V5.1
Figure 29: DC operating area.
Figure 30: Output Voltage Stability vs. Junction
Temperature.
Vout [V]
5.2
O ut put C u rr e nt [A ]
8
Vou t = 5.1V
T j = 125 °C
7
C u rre nt L im itatio n
V in = 8V
Iout = 1 0mA
5.15
6
Rd so n
lim it
5
5.1
Pow er D issip a tio n Lim it
4
5.05
T c = 2 5°C
P d m a x = 4 0W
3
5
DC O pe ratin g A re a
2
4.95
T c = 70 °C
P dm a x = 2 2W
1
4.9
0
0
2 .5
5
7 .5
10
(V in - Vou t) [V ]
1 2 .5
15
-4 0
1 7 .5
0
40
80
12 0
1 60
4
5
T j [°C ]
Figure 31: Quiescent Current vs. Temperature.
Figure 32: Load Regulation
10
Iq [mA]
3
8
Output Voltage Deviation [mV]
2 .75
2.5
2 .25
2
1 .75
1.5
1 .25
1
0 .75
6
4
2
0
-2
-4
-8
0 .25
0
-40
-10
-20
0
20
40
60
T j [°C]
80
100
1 20
140
5
Output Voltage Deviation [mV]
1
2
3
Io u t [A]
Figure 34: Maximum OutputCurrent vs. Junction
Temperaturewith internalcurrent limiting
O utput C urrent [A]
10
4.5
3.5
0
160
Figure 33: Line regulation vs. Junction Temperature.
4
V in = 8 V
Tj = 2 5 ° C
(P uls e d tec n iq u e h as be en us ed )
-6
Vin = 8V
Iout = 10mA to 5A
0.5
9
6.5V < Vin < 15V
Iout = 10mA
8
7
3
6
2.5
5
2
4
1.5
3
1
2
0.5
1
0
-40
-20
0
20
40
60
80
Tj [°C]
100 120 140 160
(Vin-Vout) > 2V
pin 2 = G ND
0
-40 -20
0
20
40
60 80 100 120 140 160
Tj [°C]
*P ulsed tecnique ha s been used
11/14
L4955
DIM.
A
C
D
D1
E
E1
F
F1
G
G1
G2
H2
H3
L
L1
L2
L3
L4
L5
L6
L7
L9
M
M1
V4
Dia
MIN.
mm
TYP.
2.4
1.2
0.35
0.7
0.6
2.34
4.88
7.42
10.05
16.7
21.24
22.27
2.6
15.1
6
2.55
4.83
2.54
5.08
7.62
16.9
14.92
21.54
22.52
2.8
15.5
6.35
0.2
2.8
5.08
3.65
MAX.
4.8
1.37
2.8
1.35
0.55
0.97
0.8
0.9
2.74
5.28
7.82
10.4
10.4
17.1
inch
TYP.
MIN.
0.094
0.047
0.014
0.028
0.024
0.095
0.193
0.295
0.396
0.657
21.84
22.77
1.29
3
15.8
6.6
0.386
0.877
3.05
5.33
40°
3.85
0.100
0.190
(typ.)
0.144
0.102
0.594
0.236
0.100
0.200
0.300
0.668
0.587
0.848
0.891
0.110
0.610
0.250
0.008
0.110
0.200
OUTLINE AND
MECHANICAL DATA
MAX.
0.189
0.054
0.110
0.053
0.022
0.038
0.031
0.035
0.105
0.205
0.307
0.409
0.409
0.673
0.860
0.896
0.051
0.118
0.622
0.260
0.120
0.210
Heptawatt V
0.152
V
L
V
E
L1
M1
A
M
D
C
D1
L5
H2
L2
L3
F
E
E1
V4
L9
H3
H1
G
G1
G2
Dia.
F
L7
L4
L6
12/14
H2
F1
HEPTAMEC
L4955
mm
MIN.
TYP.
inch
MAX.
MIN.
TYP.
MAX.
A
4.40
4.60
0.173
0.181
C
1.23
1.32
0.048
0.051
D
2.40
2.72
0.094
0.107
E
0.49
0.70
0.019
0.027
F
0.61
0.88
0.024
0.034
F1
1.14
1.70
0.044
0.067
F2
1.14
1.70
0.044
0.067
G
4.95
5.15
0.194
0.203
G1
2.40
2.70
0.094
0.106
H2
10.0
10.4
0.393
0.409
L2
16.4
0.645
L4
13.0
14.0
0.511
0.551
L5
2.65
2.95
0.104
0.116
L6
15.25
15.75
0.600
0.620
L7
6.20
6.60
0.244
0.260
L9
3.50
3.93
0.137
0.154
M
Dia
2.6
3.75
OUTLINE AND
MECHANICAL DATA
0.102
3.85
0.147
Versawatt (TO220)
0.151
M
DIM.
TO220MEC
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L4955
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