Table 9. DC Electrical Specifications1 (continued)
Input Capacitance 3
All input-only pins
All input/output (three-state) pins
Low drive strength
High drive strength
Core Operating Supply Current 5
— 25 pF
— 50 pF
135 150 mA
Pad Operating Supply Current
Low Power Modes
DC Injection Current 3, 6, 7, 8
VNEGCLAMP =VSS– 0.3 V, VPOSCLAMP = VDD + 0.3
Single Pin Limit
Total processor Limit, Includes sum of all stressed pins
1 Refer to Table 10 for additional PLL specifications.
2 Refer to the MCF5235 signals section for pins having weak internal pull-up devices.
3 This parameter is characterized before qualification rather than 100% tested.
4 pF load ratings are based on DC loading and are provided as an indication of driver strength. High speed interfaces require
transmission line analysis to determine proper drive strength and termination. See High Speed Signal Propagation:
Advanced Black Magic by Howard W. Johnson for design guidelines.
5 Current measured at maximum system clock frequency, all modules active, and default drive strength with matching load.
6 All functional non-supply pins are internally clamped to VSS and their respective VDD.
7 Input must be current limited to the value specified. To determine the value of the required current-limiting resistor, calculate
resistance values for positive and negative clamp voltages, then use the larger of the two values.
8 Power supply must maintain regulation within operating VDD range during instantaneous and operating maximum current
conditions. If positive injection current (Vin > VDD) is greater than IDD, the injection current may flow out of VDD and could
result in external power supply going out of regulation. Insure external VDD load will shunt current greater than maximum
injection current. This will be the greatest risk when the processor is not consuming power. Examples are: if no system
clock is present, or if clock rate is very low which would reduce overall power consumption. Also, at power-up, system clock
is not present during the power-up sequence until the PLL has attained lock.
MCF523x Integrated Microprocessor Hardware Specification, Rev. 4
26 Freescale Semiconductor