CMX981 Consumer Microcircuits Limited, CMX981 Datasheet - Page 52

• Manufacturer Part Number: CMX981
• Description: Advanceddigital Radio Baseband Processor (tetra Etc.)
• Manufacturer: Consumer Microcircuits Limited

Advanced Digital Radio Baseband Processor
7.1.3
Details in this section represent design target values and are not currently guaranteed.
For the following conditions unless otherwise specified:
Notes:
General Points:
 2002 CML Microsystems Plc
DC Parameters (MCLK not toggled)
AC Parameters (MCLK at 9.216MHz)
MCLK Input
I
I
I
I
I
I
I
I
I
I
I
I
I
'High' pulse width
'Low' pulse width
Input impedance (at 100Hz)
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
DD
(Tx powersaved)
(Rx powersaved)
(Aux powersaved)
(Codec powersaved)
(All powersaved)
(Not powersaved)
(Tx powersaved)
(Rx powersaved)
(Aux powersaved)
(Codec powersaved)
(All powersaved except serial clock)
(All powersaved)
(Not powersaved)
Operating Characteristics
Xtal Frequency = 9.216MHz, Bit Rate = 36k bits/sec, Voice codec speaker and earpiece drivers
disabled.
V
2.75V. Tamb = - 40°C to +85°C.
DD
1. Not including any current drawn from the device pins by external circuitry.
2. Timing for an external input to the MCLK pin.
3. The current quoted when MCLK is not toggled is essentially analogue current (digital
4. The bias chain must be powered up in order to power up the Aux ADC, Tx, Rx and Codec
5. Currents in other modes can be calculated from the above figures. For example, operation
6. Supply currents for other MCLK frequencies can be calculated by assuming the analogue
- V
SS
current is negligible in this case), while the current quoted when MCLK is toggled is a
combination of analogue and digital current.
sections, but NOT the auxiliary section. It is recommended that the bias chain is powered
up at least 1ms before powering up the Aux ADC, Tx, Rx or Codec. Powering down the
bias chain reduces current by 10-15 A
with Tx and auxiliary sections powersaved:
From the table, auxiliary current is approximately 1.5mA (18 - 16.5mA).
Subtracting this from Tx powersaved current (12.25mA) gives a predicted current of
10.75mA.
current is constant and the digital current is proportional to MCLK frequency.
= V
CC1
- V
SS1
= V
CC2
- V
SS2
= V
CC3
52
Notes
- V
1
1
1
1
1
1
1
1
1
1
1
1
1
2
2
SSB
= V
Min.
30.0
30.0
10.0
DD1
- V
SSA
Typ.
10.0
12.0
17.0
17.0
18.0
6.0
5.0
9.0
9.0
9.0
2.0
1.0
-
= V
DDPA
Max.
- V
10.0
14.0
14.0
50.0
16.0
19.0
14.0
26.0
27.0
29.0
8.0
3.0
2.0
SSPA
= 2.25V to
CMX981
D/981/1
Units
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
mA
M
µA
ns
ns