HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : Preliminary Data
Issued Date : 1998.06.01
Revised Date : 2000.10.01
Page No. : 1/6
HSMC Product Specification
H1117J Series
1A LOW DROPOUT POSITIVE VOLTAGE REGULATOR
Features
Low Dropout Voltage 1.2V at 1A
Adjustable or Fixed Voltage
Maximum Line Regulation 0.45%
Maximum Load Regulation 0.4%
Adjust Pin Current Less Than 90 uA
Over Current Protection
Thermal Protection
Applications
High Efficiency Linear Regulators
5V to 3.3V Voltage Converter
Battery Charger
General Description
The H1117J is a 1A low-dropout positive voltage regulator. It is available in fixed and adjustable output voltage
versions. Over current and thermal protection are integrated onto the chip. Output current will decrease while it
reaches the pre-set current or temperature limit. The dropout voltage is specified at 1.2V Maximum at full rated
output current. H1117J Series provides excellent regulation over variations due to changes in line, load and
temperature. H1117J is three terminal regulator and available in popular packages.
Device Selection Guide
Device
Output Voltage
Package
H1117J(Adj)
1.3V to 4V
H1117-3.3J
3.3
D-PAK
TO-252
Absolute Maximum Ratings
Parameter
Symbol
Maximum
Units
Input Voltage
V
IN
20
V
Power Dissipation
P
D
Internally Limited
W
Thermal Resistance Junction To Case TO-252
JC
15
C/W
Thermal Resistance Junction To Ambient TO-252
JA
156
C/W
Operating Junction Temperature Range
T
j
0 To 125
C
Storage Temperature Range
T
STG
-65 To 150
C
Lead Temperature (Soldering) 10 Sec
T
LEAD
260
C
Typical Application
+
H1117J
10uF
TAN
10uF
TAN
4.75V
to 20V
DC
GND
Load
Input Range Depends On V
O
Please Refer To Electrical Characteristics.
HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : Preliminary Data
Issued Date : 1998.06.01
Revised Date : 2000.10.01
Page No. : 4/6
HSMC Product Specification
Applications Description
Output Voltage Adjustment
Like most regulators, the H1117J regulates the output by
comparing the output voltage to an internally generated
reference voltage. On the adjustable version, the V
REF
is
available externally as 1.25V between V
OUT
and ADJ. The
voltage ratio formed by R
1
and R
2
should be set to conduct
10mA (minimum output load). The output voltage is given
by the following equation : V
OUT
=V
REF
(1+R
2
/R
1
) + I
ADJ
R
2
On fixed versions of H1117J, the voltage divider is
provided internally.
Thermal Protection
H1117J has thermal protection which limits junction
temperature to 150
C. However, device functionality is
only guaranteed to a maximum junction temperature of
+125
C.
The power dissipation and junction temperature for H1117J in TO-252 package given by
P
D
=(V
IN
- V
OUT
) I
OUT
, T
JUNCTION
=T
AMBIENT
+(P
D
x
JA
), Note : T
JUNCTION
must not exceed 125
C
Current Limit Protection
H1117J is protected against overload conditions. Current protection is triggered at typically 1.5A.
Stability And Load Regulation
H1117J requires a capacitor from V
OUT
to GND to provide
compensation feedback to the internal gain stage. This is
to ensure stability at the output terminal. Typically, a 10uF
tantalum or 50uF aluminum electrolytic is sufficient.
Note : It is important that the ESR for this capacitor does
not exceed 0.5
.
The output capacitor does not have a theoretical upper
limit and increasing its value will increase stability. C
OUT
=
100 uF or more is typical for high current regulator design.
H1117J load regulation is limited by the resistance of the
wire connecting it to the load(R
P
). For the adjustable
version, the best load regulation is accomplished when the
top of the resistor divider(R
1
) is connected directly to the
output pin of the H1117J. When so connected, R
P
is not
multiplied by the divider ratio. For fixed output versions,
the top of R
1
is internally connected to the output and ground pin can be connected to low side of the load as a
negative side sense if, so desired.
Thermal Consideration
The H1117J series contain thermal limiting circuitry designed to protect itself for over-temperature conditions.
Even for normal load conditions, maximum junction temperature ratings must not be exceeded. As mention in
thermal protection section, we need to consider all sources of thermal resistance between junction and ambient.
It contains junction-to-case, case-to-heat-sink interface and heat sink resistance itself. An additional heat sink is
applied externally sometimes. It can increase the maximum power dissipation. For example, the equivalent
junction temperature of 300mA output current is 115
C without external heat sink. Under the same junction
temperature IC can operates 500mA with an adequate heat sink. Therefore, to attach an extra heat sink is
recommended.
Junction-to-case thermal resistance is specified from the IC junction to the bottom of the case directly below the
die. The bonding wires are appending paths. The former is the lowest resistance path. Proper mounting is
required to ensure the best possible thermal flow this area of the package to the heat sink. Thermal compound at
the case-to-heat-sink interface is strongly recommended. The case of all devices in this series is electrically
connected to the output. Therefore, if the case of the device must be electrically isolated, a thermally conductive
spacer can be used, as long its thermal resistance is considered.
RL
R1
R2
Connect
R1 to Case
Connect
R2 to Load
Out
In
Adj
R
P
Parasitic
Line Resistance
V
IN
V
OUT
=V
REF
(1+R
2
/R
1
) + I
ADJ
R
2
V
IN
R1
R2
V
REF
In
Out
ADJ
I
ADJ
10uA
V
OUT
HI-SINCERITY
MICROELECTRONICS CORP.
Spec. No. : Preliminary Data
Issued Date : 1998.06.01
Revised Date : 2000.10.01
Page No. : 5/6
HSMC Product Specification
Protection Diode
(The figure is shown as Regulator with Reverse Diode Protection in advanced applications)
In general operation, H1117J does not need any protection diodes. From the cross-section structure of H1117J,
the output pin is connected to P+ substrate, and the input pin is connected to N- well. There is a parasitic reverse
diode between them. It can handle microsecond surge currents of 5A to 10A. Even with large output capacitance,
it is very difficult to get those values of surge currents in normal operation. Only with high value output capacitors,
such as 1000uF. And with the input pin instantaneously shorted to ground. can damage occur. A crowbar circuit
at the input of the H1117J can generate those kinds of currents, and a diode from output to input is
recommended. Normal power supply cycling or even plugging and unplugging in the system will not generate
currents large enough to do any damage.
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