TC1728 Datasheet, PDF (84/130 Pages) Infineon Technologies AG – 32-Bit Single-Chip Microcontroller

5.2.4 Oscillator Pins
TC1728
Electrical Parameters
Table 25 OSC_XTAL Parameters
Parameter
Symbol
Values
Min. Typ. Max.
Unit Note /
Test Condition
Input current at XTAL1 I_IX1 CC -25 − 25
Input frequency
f_OSC SR 4
− 40
μA
MHz
V_IN> 0 V;
V_IN<V_DDP
Direct Input
Mode selected
8
−
Oscillator start-up time¹⁾ t_OSCS CC −
−
Input high voltage at
XTAL1²⁾
V_IHX SR 0.7 x −
V_DDP
Input low voltage at
XTAL1
V_ILX SR -0.5 −
Input hysteresis for
HYSAX −
−
XTAL1 pad³⁾
CC
25
10
V_DDP +
0.5
0.3 x
V_DDP
200
MHz External Crystal
Mode selected
ms
V
V
mV
1) t_OSCS is defined from the moment when V_DDP = 3.13V until the oscillations reach an amplitude at XTAL1 of 0.3
* V_DDP. The external oscillator circuitry must be optimized by the customer and checked for negative resistance
as recommended and specified by crystral suppliers.
2) If the XTAL1 pin is driven by a crystal, reaching a minimum amplitude (peak-to-peak) of 0.3 * V_DDP is
necessary.
3) Hysteresis is implemented to avoid metastable states and switching due to internal ground bounce. It can´t be
guaranteed that it suppresses switching due to external system noise.
Note: It is strongly recommended to measure the oscillation allowance (negative
resistance) in the final target system (layout) to determine the optimal parameters
for the oscillator operation. Please refer to the limits specified by the crystal or
ceramic resonator supplier.
Data Sheet
5-38
V1.2, 2014-06