IKSEMICON ILE4271-2

TECHNICAL DATA
5-V LOW-DROP FIXED VOLTAGE REGULATOR
ILE4271-2
Functional Description
The device is a 5-V low-drop fixed-voltage regulator. The
maximum input voltage is 42 V (65 V, ≤400 ms). Up to an input
voltage of 26 V and for an output current up to 550 mA it regulates
the output voltage within a 2% accuracy. The short circuit
protection limits the output current of more than 650 mA.
The IC can be switched off via the inhibit input. An integrated
watchdog monitors the connected controller. The device
incorporates overvoltage protection and temperature protection
that disables the circuit at unpermissibly high temperatures.
Features
• Output voltage tolerance ≤± 2%
• Low-drop voltage
• Integrated overtemperature protection
• Reverse polarity protection
• Input voltage up to 42 V
• Overvoltage protection up to 65 V (≤ 400 ms)
• Short-circuit proof
• Suitable for use in automotive electronics
• Wide temperature range
• Adjustable reset and watchdog time
Pin Definitions and Functions
Pin
Symbol
Function
1
I
2
INH
Inhibit
3
RO
Reset Output; the open collector output is connected to the
5 V output via an integrated resistor of 30 kOhm
4
GND
5
D
Reset Delay; connect a capacitor to ground for delay time adjustment.
6
W
Watchdog Input
7
Q
5-V Output; block to ground with 22 uF capacitor, ESR < 3 Ohm.
Input; block to ground directly on the IC with ceramic capacitor.
Ground
1
ILE4271-2
Application Description
The IC regulates an input voltage in the range of 5.5 V < VI < 36 V to VQnom = 5.0 V. Up to
26 V it produces a regulated output current of more than 550 mA. Above 26 V the saveoperating-area protection allows operation up to 36 V with a regulated output current of
more than 300 mA. Overvoltage protection limits operation at 42 V. The overvoltage
protection hysteresis restores operation if the input voltage has dropped below 36 V. The
IC can be switched off via the inhibit input, which causes the quiescent current to drop
below 50 uA. A reset signal is generated for an output voltage of VQ < 4.5 V. The
watchdog circuit monitors a connected controller. If there is no positive-going edge at the
watchdog input within a fixed time, the reset output is set to low. The delay for power-on
reset and the maximum permitted watchdog-pulse period can be set externally with a
capacitor.
Design Notes for External Components
An input capacitor CI is necessary for compensation of line influences. The resonant
circuit consisting of lead inductance and input capacitance can be damped by a resistor
of approx. 1 Ohm in series with CI. An output capacitor CQ is necessary for the stability of
the regulating circuit. Stability is guaranteed at values of CQ ≤22 uF and an ESR of <3
Ohm.
Circuit Description
The control amplifier compares a reference voltage, which is kept highly accurate by
resistance adjustment, to a voltage that is proportional to the output voltage and drives the
base of a series transistor via a buffer. Saturation control as a function of the load current
prevents any over-saturation of the power element.
If the output voltage decreases below 4.5 V, an external capacitor CD on pin 4 (D) will be
discharged by the reset generator. If the voltage on this capacitor VD drops below VDRL,
a reset signal is generated on pin 2 (RO), i.e. reset output is set low. If the output voltage
rises above 4.5 V, CD will be charged with constant current. After the power-on-reset time
VD reaches VDU and the reset output will be set high again. The value of the poweron-reset time can be set within a wide range depending on the capacity of CD. The value of
the pull-up resistor at reset output is typically 30 kOhm.
After VD has reached the voltage VDU and reset was set to high, the watchdog circuit is
enabled and discharges CD with a constant current. If there is no positive-going edge
observed at watchdog input, CD will be discharged down to VDWL. Then reset will be set
low and the watchdog circuit will be disabled. CD will be charged with the current as at
power-on reset until VD reaches VDU and reset will be set high again.
If a watchdog pulse will be observed before CD is discharged down to VDWL, the watchdog
circuit will be enabled and CD will be charged too, but reset will not be set low. After VD
has reached VDU, the periodical behavior starts again.
The IC also incorporates a number of internal circuits for protection against:
•
•
•
•
Overload
Overvoltage
Overtemperature
Reverse polarity
2
ILE4271-2
Block Diagram
3
ILE4271-2
Maximum & Absolute Maximum Ratings
Maximum Ratings
Parameter Symbol
Unit
Inhibit voltage, UINH
V
Input current, II
A
min.
-40
6
-
Output voltage, UQ
Output current, IQ
V
mA
4,9
-5
Current on common pin ,IGND
Reset voltage, UR
Reset current, IR
mA
V
A
4,9
-5
V
mA
V
mA
o
C /W
-
max.
125
36
internally
limited
5,1
internally
limited
5,1
internally
limited
70**
°С/W
-
3**
Junction temperature, ТJ
Storage temperature, ТS
Input voltage, VI
Output voltage, UQ
Output current, IQ
Output voltage, UQ
Output current, IQ
Thermal resistance junction ambient
(P-TO-263-7-1), Rth ja,
Thermal resistance junction case
(P-TO-263-7-1), Rth jc
o
C
o
C
V
Absolute Maximum
Ratings
min.
max.
-40
150
-50
150
-42
42
65*
internally
limited
-1
16
-5
internally
limited
-0.5
–
-1
16
-5
internally
limited
-0.3
7
-5
5
-0.3
7
-5
5
70**
-
3**
* Time of influence t ≤ 400ms
** Thermal resistance junction ambient for IC with heat dissipater is calculated by formula:
Rth ja = Rth jc + Rth ca (1)
Rth jc - thermal resistance junction case, oC /W.
Application circuit and heat dissipater have to provide TJ ≤ 125 ОС.
Maximum power Ptot,Вт, dissipated by IC for TA , is calculated by formula:
Ptot = (125 - TA) / Rth ja (2)
125 – maximum permitable operating junction temperature, ОС.
4
ILE4271-2
Optimum reliability and life time are guaranteed if the junction temperature does not
exceed 125 oC in operating mode. Operation at up to the maximum junction temperature
of 150 oC is possible in principle. Note, however, that operation at the maximum permitted
ratings could affect the reliability of the device.
Operating Range
Parameter
Symbol
Input voltage
Junction temperature
Thermal Resistance
Junction ambient
VI
Tj
Rthja
Limit Values
min.
max.
6
40
– 40
150
Rthjc
–
65
70
3
Zthjc
–
2
Junction case
–
Unit
Notes
V
C
–
–
K/W
K/W
K/W
–
P-TO263
–
K/W
t <1 ms
o
Characteristics
VI = 13.5 V; – 40 oC ≤Tj ≤125 oC (unless otherwise specified)
Parameter, unit
Output voltage, V
Output current limiting, mA
Current
consumption, мкА,
Iq = II
Current
consumption, mA
Iq = II - IQ
Drop voltage, V
Load regulation, mV
Supply voltage
regulation, mV
Symbol
Test Condition
VQ
6V≤VI ≤26V;
5mA≤IQ≤550mA
26V≤VI ≤36V; IQ≤300mA
VQ=0В
Ve=0В; IQ=0mA
IQmax
Iq
VDr
∆VQ(I)
∆UQ(U)
IQ=5mA
IQ=550mA
IQ=550mA; VI=5V
IQ=550mA
5мА ≤ IQ ≤ 550mA
VI = 6 V
6B≤ UI ≤ 26V
IQ=5mA
Limit Values
Min.
Max.
4.90
5.10
4.90
650
Note
5.10
50
1,5
75
90
0.7
50
3
25
5
ILE4271-2
Parameter, unit
Symbol
Test Condition
Inhibit
Inhibit ON voltage, V
VINH,on
UQ >4.5V
Inhibit OFF voltage, V
VINH,off
UQ <0.8V
IINH
UINH=5V
Inhibit current, uA
Overvoltage protection
Напряжение выключения, В
Watchdog
Upper timing threshold, V
Lower watchdog timing
threshold, V
Discharge current, uA
Charge current, uA
Watchdog period, ms
Watchdog trigger time, ms
Reset Generator
Switching threshold, V
Reset high voltage, V
Reset low voltage, V
Resistance of circuit, kOhm
Lower reset timing threshold,
V
Upper reset timing threshold,
V
Delay time, ms
Charge current, uA
Limit Values
Min.
Max.
3,5
0,8
8
25
VI, OV
40
46
VDU
VDWL
1.4
0.2
2.3
0.8
1.5
8
40
30
3.5
25
75
66
4.5
4.5
18
4.8
400
46
0.2
0.8
1.4
2.3
8
8
18
25
Idis
Id
tw
twt
VRT
VROH
VROL
R
VDRL
UD=1V
UD=1V
CD=100 nF
CD=100 nF
IR=3mA, VQ=4.4V
Direct connection to
pin Q
VQ < VRT
VDU
td
Id
CD = 100 nF
VD = 1.0 V
Note
Notes
1 Following capacitances are connected:
on input C1I = 1000 uF(electrolytic), C2I = 470 nF
on output CQ = 22 uF (electrolytic).
2 Measurements of parameters have to carry out with pulse equipment.
3 Drop voltage VDr= VI - VQ (measured when the output voltage has dropped 100 mV from the nominal
value obtained at 13.5 V input)
1)
6
ILE4271-2
Test Circuit
Application Circuit
7
ILE4271-2
Time Response
Time Response, Watchdog Behavior
8
ILE4271-2
Package Dimensions
P-TO 220-7-180
9