LT1236CIS8-5#TR Linear Technology, LT1236CIS8-5#TR Datasheet - Page 8

• Manufacturer Part Number: LT1236CIS8-5#TR
• Description: IC REF PREC 5V 15PPM/DEGC 8SOIC
• Manufacturer: Linear Technology

Specifications of LT1236CIS8-5#TR

• Reference Type: Series, Shunt
• Voltage - Output: 5V
• Tolerance: ±0.1%
• Temperature Coefficient: 15ppm/°C
• Voltage - Input: 7.2 ~ 40 V
• Number Of Channels: 1
• Current - Quiescent: 1.2mA
• Current - Output: 10mA
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Cathode: -

LT1236
APPLICATIONS
Kelvin Connections
Although the LT1236 does not have true force/sense
capability at its outputs, significant improvements in ground
loop and line loss problems can be achieved with proper
hook-up. In series mode operation, the ground pin of the
LT1236 carries only 1mA and can be used as a sense
line, greatly reducing ground loop and loss problems on
the low side of the reference. The high side supplies load
current so line resistance must be kept low. Twelve feet of
#22 gauge hook-up wire or 1 foot of 0.025 inch printed
circuit trace will create 2mV loss at 10mA output current.
This is equivalent to 1LSB in a 10V, 12-bit system.
The following circuits show proper hook-up to minimize
errors due to ground loops and line losses. Losses in the
output lead can be greatly reduced by adding a PNP boost
transistor if load currents are 5mA or higher. R2 can be
added to further reduce current in the output sense lead.
Effects of Air Movement on Low Frequency Noise
The LT1236 has very low noise because of the buried zener
used in its design. In the 0.1Hz to 10Hz band, peak-to-peak
noise is about 0.5ppm of the DC output. To achieve this
low noise, however, care must be taken to shield the
reference from ambient air turbulence. Air movement can
create noise because of thermoelectric differences be-
tween IC package leads and printed circuit board materials
and/or sockets. Power dissipation in the reference, even
though it rarely exceeds 20mW, is enough to cause small
8
TYPICAL APPLICATIONS
TRIM RANGE
Restricted Trim Range for Improved
V
Resolution, 10V, “A” Version Only
IN
IN
LT1236A-10
GND
TRIM
10mV
OUT
75k
R1
U
INFORMATION
R2
50k
LT1236 TA10
10.000V
U
U
W
LT1236-10 Full Trim Range ( 0.7%)
V
IN
*
CAN BE RAISED TO 20k FOR LESS
CRITICAL APPLICATIONS
U
IN
GND
LT1236-10
TRIM
OUT
temperature gradients in the package leads. Variations in
thermal resistance, caused by uneven air flow, create
differential lead temperatures, thereby causing thermo-
electric voltage noise at the output of the reference.
GROUND
RETURN
R1*
10k
LT1236 TA03
INPUT
V
OUT
*OPTIONAL—REDUCES CURRENT IN OUTPUT SENSE
LEAD: R2 = 2.4k (LT1236-5), 5.6k (LT1236-10)
GROUND
RETURN
Series Mode with Boost Transistor
IN
INPUT
LT1236
GND
Standard Series Mode
LT1236
OUT
GND
–15V
IN
R1
220
OUT
KEEP THIS LINE RESISTANCE LOW
Negative Series Reference
4.7k
R2
R2*
2N2905
2N3906
15V
Q1
R1
4.7k
D1
15V
LOAD
LT1236 AI04
IN
LT1236-10
GND
LT1236 AI03
LOAD
OUT
+
–10V AT
50mA
LT1236 TA04