LTC1967IMS8 Linear Technology, LTC1967IMS8 Datasheet - Page 24

• Manufacturer Part Number: LTC1967IMS8
• Description: IC CONVERTER RMS-DC PREC 8MSOP
• Manufacturer: Linear Technology

Specifications of LTC1967IMS8

• Current - Supply: 320µA
• Voltage - Supply: 5.0V
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

APPLICATIO S I FOR ATIO
LTC1967
TROUBLESHOOTING GUIDE
Top Ten LTC1967 Application Mistakes
1. Circuit won’t work–Dead On Arrival–no power drawn.
2. Circuit won’t work, but draws power. Zero or very
3. Screwy results, particularly with respect to linearity
24
– Probably forgot to enable the LTC1967 by pulling
little output, single-ended input application.
– Probably didn’t connect both input pins.
or high crest factors; differential input application.
– Probably AC-coupled both input pins.
Pin 8 low.
Solution: Tie Pin 8 to Pin 1.
Solution: Tie both inputs to something. See “Input
Connections” in the Design Cookbook.
Solution: Make at least one input DC-coupled. See
“Input Connections” in the Design Cookbook.
DC-COUPLE ONE INPUT
2
3
IN1
IN2
LTC1967
U
CONNECT PIN 3
NC
U
2
3
IN1
IN2
LTC1967
1967TS02
W
DC-CONNECT ONE INPUT
2
3
IN1
IN2
LTC1967
U
1967 TS03
4. Gain is low by a few percent, along with other screwy
5. Offsets perceived to be out of specification because 0V
6. Linearity perceived to be out of specification particu-
results.
– Probably tried to use output in a floating, differential
in 0V out.
– The offsets are not specified at 0V in. No RMS-to-
larly with small input signals.
– This could again be due to using 0V in as one of the
– The input offset voltage can cause small AC linear
manner.
Solution: Tie Pin 6 to a low impedance. See “Output
Connections” in the Design Cookbook.
DC converter works well at 0 due to a divide-by-zero
calculation.
Solution: Measure V
ings > 5mV
measurement points.
Solution: Check Linearity from 5mV
500mV
ityerrors at low input amplitudes as well. See “Error
Analyses” section.
Possible Solution: Include a trim for input offset.
RMS
OUT RTN
.
LTC1967
DC
V
OUT
.
GROUND PIN 6
5
6
IOS
/V
31
30
OOS
HI
LO
TYPE 7136
ADC
by extrapolating read-
1967 TS04
RMS
1967f
to