X90100M8I Intersil, X90100M8I Datasheet - Page 5

• Manufacturer Part Number: X90100M8I
• Description: IC DIGITAL CAPACITOR NV 8-MSOP
• Manufacturer: Intersil

Specifications of X90100M8I

• Applications: *
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Power Up Timing (Digital Inputs Floating, Internal Pullup Action Shown)
Power Up and Down Requirements
There are no restrictions on the power-up or power-down
conditions of V
pins provided that V
to V
is always in effect.
Powerup Requirements
In order to prevent unwanted tap position changes or an
inadvertant store, bring the CS and INC high before or
concurrently with the V
active pullups to provide reliable powerup operation. See
powerup timing diagram.
Pin Configuration
Detailed Pin Descriptions
Cp and Cm
The high (Cp) and low (Cm) terminals of the X90100 are
equivalent to the fixed terminals of a mechanical trimmable
capacitor. The minimum dc voltage is V
is V
determined by digital inputs INC, U/D, and CS.
Up/Down (U/D)
The U/D input controls the direction of the trimmed capacitor
value and whether the counter is incremented or
decremented. This pin has an active current source pullup.
CC
Cp
, V
. The value of capacitance across the terminals is
Cm
Vss
INC
U/D
Cp
, i.e., V
CC
and the voltages applied to the Cp, Cm
CC
1
2
3
4
CC
≥ V
CC
is always more positive than or equal
X90100
MSOP
Cp
pin. The logic inputs have internal
, V
5
V
Cm
CC
8
7
6
5
= 3.3 or 5.0V
. The V
V
INC
U/D
CS
CC
V
CS
N/C (leave floating)
Cm
SS
CC
CC
and the maximum
ramp rate spec
X90100
t
R
V
CC
Increment (INC)
The INC input is negative-edge triggered. Toggling INC will
move the capacitance value and either increment or
decrement the counter in the direction indicated by the logic
level on the U/D input. This pin has an active current source
pullup.
Chip Select (CS)
The device is selected when the CS input is LOW. The
current counter value is stored in nonvolatile memory when
CS is returned HIGH while the INC input is also HIGH. After
the store operation is complete the X90100 will be placed in
the low power standby mode until the device is selected
once again. This pin has active circuit source pullup.
N/C - This pin should be left floating.
Principles of Operation
There are three sections of the X90100: the input control,
counter and decode section; the nonvolatile memory; and
the capacitor array. The input control section operates just
like an up/down counter. The output of this counter is
decoded to turn on electronic switches connecting internal
units to the sum capacitor. Under the proper conditions the
contents of the counter can be stored in nonvolatile memory
Pin Names
SYMBOL
V CC
V SS
U/D
INC
Cm
CS
Cp
DEFAULT
supply
supply
pull up
pull up
pull up
output
output
Positive capacitor terminal
Negative capacitor terminal
Ground
Positive supply voltage
Up/Down control input
Increment control input
Chip Select control input
DESCRIPTION
February 2, 2005
FN8156.0