WE2408 View Datasheet(PDF) - Unspecified
Part Name
Description
MFG CO.
'WE2408' PDF : 36 Pages View PDF
WiNEDGE & WiRELESS
Winceiver WE2408
2.4GHz Single Chip FM Transceiver
Otherwise, the follow approximated values can be used:
RVCO (1.8GHz), Kvco = 40MHz/V;
TVCO (800MHz), Kvco = 23MHz/V.
Charge Pump Current
The available charge pump current settings are 0.2mA and 1.0mA for both Tx and Rx. The charge
pump current is selected by programming the Mode register bits 6 (Rx) and 7 (Tx).
With proper consideration on damping factor, higher charge pump current reduces PLL lock time.
Reference Frequency
In general, larger reference frequency reduces PLL lock time. It is set by Reference Frequency
Register.
RECEIVER ATTACK TIME
Rx Baseband DC Offset Loop Response Time
Settling time is 2ms for an effective receiver baseband HPF of 100Hz. The HPF can be adjusted with
changing the external capacitors on DCI/DCQ. Settling time will be approximately inversely
proportional to the DCI/DCQ capacitors. When making such changes, consideration must be given to
the required high pass filtering for the lowest possible frequency of the FM signal.
Auto Gain Control Response Time
Similar considerations should be applied as in RSSI settling time. Current recommendation is to set
up the receiver to allow a gain change every 14ms for a receive bandwidth of 130kHz and every 56ms
for a bandwidth of 16kHz. Note this only changes the gain by 1 step. It could take 8x as long (110ms
or 450ms) to get from maximum to minimum gain or from minimum to maximum gain.
Note that the gain is automatically set to maximum whenever the serial interface signal LE goes high
unless this gain reset is disable by programming the Mode register.
More information is available in section on Rx Gain Control and Mode Register.
© 2003 WiNEDGE & WiRELESS PTE LTD
Rev Date: 2003 May 23
Page 19
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