CHR2244-QDG_15 Datasheet, PDF (6/14 Pages) United Monolithic Semiconductors – 5.8 GHz One Antenna Reflective Transponder for Tag

CHR2244-QDG
5.8 GHz One Antenna Reflective Tag
All of the different inputs (TR, Mod) and outputs (SB_out, DATA_out) should be properly isolated
(separated enough or with a ground path between them).
As T/R port is the most sensitive one, a specific circuit (see on diagram) can be used for high level
of isolation.
Device slug should be connected to RF ground plane through multiples vias (>=9).
An external matching may be required to optimize RF performances on 50Ω impedance, versus
substrate height. A RF ground plane height of 0.008” (0.203mm) under the component (evaluation
board) provides the highest RF performances thanks to low RF ground inductance and low pin to
pin coupling.
Adjustment abilities
Pin number Pin name Component
Description
Standby sensitivity adjust port:
7
SENS
R3
A value lower than 2.2MΩ decreases Standby chain
sensitivity.
Standby amplifiers Gain adjust por :
12
Ga_SB
R4
A value lower than 680kΩ increases Standby chain
sensitivity.
Downlink threshold adjust port:
19
AD
R5
A value lower than 6.8MΩ decreases Downlink chain
sensitivity.
Downlink amplifiers Gain adjust port:
20
Ga_WK
R6
A value lower than 220 kΩ increases Downlink chain
sensitivity.
IMPORTANT NOTICE:
All this adjustments may cause non linear response of the performances versus resistors values. The
sensitivity is –1x (Minimum RF power for considered mode). Indeed, a decrease of the sensitivity
means an increase of the minimum RF power for considered mode.
Ref. : DSCHR2244-QDG9030 - 30 Jan 09
6/14
Specifications subject to change without notice
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