Datasheet

LTC6991
8
6991fb
BLOCK DIAGRAM
(S6 package pin numbers shown)
6991 BD
PROGRAMMABLE
DIVIDER
FIXED
DIVIDER
÷ 1024
÷1, 8, 64, 512
4096, 2
15
, 2
18
, 2
21
MASTER OSCILLATOR
POR
OUTPUT
POLARITY
INPUT
POLARITY
DIGITAL
FILTER
4-BIT A/D
CONVERTER
POL BIT
R1
R2
DIV
V
+
OUT
5
4
1
6
HALT OSCILLATOR
IF I
SET
< 500nA
MCLK
t
MASTER
=
1µs
50k
V
SET
I
SET
=
+
–
I
SET
I
SET
V
SET
= 1V
+
–
1V
3 22
GNDSET
RST
R
SET
DQ
R
V
+
t
OUT
PIN FUNCTIONS
(DCB/S6)
GND (Pin 5/Pin 2): Ground. Tie to a low inductance ground
plane for best performance.
OUT (Pin 6/Pin 6): Oscillator Output. The OUT pin swings
from GND to V
+
with an output resistance of approximately
30. When driving an LED or other low impedance load
a series output resistor should be used to limit source/
sink current to 20mA.