TWR-56F8257 Freescale Semiconductor, TWR-56F8257 Datasheet - Page 69

• Manufacturer Part Number: TWR-56F8257
• Description: TOWER SYSTEM KIT MC56F8257
• Manufacturer: Freescale Semiconductor
• Type: DSC, Digital Signal Controllerr

Specifications of TWR-56F8257

• Contents: Board, Cables, Documentation, DVD
• For Use With/related Products: Freescale Tower System, MC56F8257
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

7.25.1
Figure 31
phases and operate at the ADC clock frequency. Equivalent input impedance, when the input is selected, is as follows:
where k =
and C
Freescale Semiconductor
1
2
3
4
5
6
7
8
9
Input impedance
AC Specifications
Signal-to-noise ratio
Total Harmonic Distortion
Spurious Free Dynamic Range
Signal-to-noise plus distortion
Effective Number Of Bits
Speed register setting must be 00 for ADC clock 5 MHz, 01 for 5 MHz < ADC clock 12 MHz, and 10 for ADC clock > 12 MHz
ADC PGA gain is x1
All measurements were made at V
Includes power-up of ADC and V
ADC clock cycles
INL and DNL measured from V
LSB = Least Significant Bit = 0.806 mV at x1 gain
Pin groups are detailed following
The current that can be injected or sourced from an unselected ADC signal input without affecting the performance of the ADC
Analog input
•
•
1.
gain
1 for first sample
6 for subsequent samples
Parasitic capacitance due to package, pin-to-pin, and pin-to-package base coupling: 1.8 pF
is as described in note 4 below.
illustrates the ADC input circuit during sample and hold. S1 and S2 are always opened/closed at non-overlapping
1
Equivalent Circuit for ADC Inputs
Parameter
9
2
(gain of 1x, 2x, 4x and f
(2 x k / ADCClockRate x C
125-ohm ESD
resisto
IN
MC56F825x/MC56F824x Digital Signal Controller, Rev. 3
REF
Table
= V
DD
3
r
REFL
= 3.3V, V
17.
Table 41. ADC Parameters
to V
equivalent resistance
IN
(V
ADC
REFH
REFHx
= V
Symbol
Channel Mux
SINAD
ENOB
SFDR
SNR
THD
100 ohms
X
REFH
= 3.3V, and V
IN
10 MHz)
- V
REFLx
gain
) / 2
4
) + 100 ohms + 125 ohms
Min
—
—
—
—
—
—
REFL
= ground
1
(continued)
S2
S1
S1
See
Figure 31
Typ
9.5
59
64
65
59
S2
C1
C1
C1: Single Ended Mode
2XC1: Differential Mode
C1: Single Ended Mode
2XC1: Differential Mode
S/H
Max
—
S1
S1
Specifications
Ohms
Unit
Bits
dB
dB
dB
dB
Eqn. 1
69