MC56F836 Freescale Semiconductor, Inc, MC56F836 Datasheet - Page 164

• Manufacturer Part Number: MC56F836
• Description: 56f8300 16-bit Digital Signal Controllers
• Manufacturer: Freescale Semiconductor, Inc

10.17 Power Consumption
This section provides additional detail which can be used to optimize power consumption for a given
application.
Power consumption is given by the following equation:
A, the internal [static component], is comprised of the DC bias currents for the oscillator, leakage current,
PLL, and voltage references. These sources operate independently of processor state or operating
frequency.
B, the internal [state-dependent component], reflects the supply current required by certain on-chip
resources only when those resources are in use. These include RAM, Flash memory and the ADCs.
C, the internal [dynamic component], is classic C*V
56800E core and standard cell logic.
D, the external [dynamic component], reflects power dissipated on-chip as a result of capacitive loading
on the external pins of the chip. This is also commonly described as C*V
of the IO cell types used on the device reveal that the power-versus-load curve does have a non-zero
Y-intercept.
164
Total power =
1.
2.
3.
4.
Parasitic capacitance due to package, pin-to-pin and pin-to-package base coupling; 1.8pf
Parasitic capacitance due to the chip bond pad, ESD protection devices and signal routing; 2.04pf
Equivalent resistance for the ESD isolation resistor and the channel select mux; 500 ohms
Sampling capacitor at the sample and hold circuit. Capacitor C1 is normally disconnected from the input and is only
connected to it at sampling time; 1pf
Analog Input
+D: external [dynamic component]
+B: internal [state-dependent component]
+C: internal [dynamic component]
+E: external [static]
A: internal [static component]
1
Figure 10-22 Equivalent Circuit for A/D Loading
2
56F8365 Technical Data, Rev. 7
(V
REFH
3
- V
REFLO
2
*F CMOS power dissipation corresponding to the
) / 2
S1
S2
4
S3
C1
C2
S/H
2
*F, although simulations on two
C1 = C2 = 1pF
Freescale Semiconductor
Preliminary