DS87C550 Datasheet, PDF (35/50 Pages) Dallas Semiconductor – EPROM High-Speed Micro with A/D and PWM

DC ELECTRICAL CHARACTERISTICS
Input Leakage Port 0, Bus
Mode
I_L
-300
RST Pulldown Resistance
R_RST
50
+300
170
DS87C550
µA
9
kO
NOTES FOR DS87C550 DC ELECTRICAL CHARACTERISTICS:
All parameters apply to both commercial and industrial temperature operation unless otherwise noted.
1. Voltage referenced to digital ground (GND).
2. Active current measured with 33 MHz clock source on XTAL1, V_CC=RST=5.5V, other pins
disconnected.
3. Idle mode current measured with 33 MHz clock source on XTAL1, V_CC=5.5V, RST at ground, other
pins disconnected.
4. Stop mode current measured with XTAL1 and RST grounded, V_CC=5.5V, all other pins disconnected.
This value is not guaranteed. Users that are sensitive to this specification should contact Dallas
Semiconductor for more information.
5. When addressing external memory.
6. RST=V_CC. This condition mimics operation of pins in I/O mode. Port 0 is tristated in reset and when
at a logic high state during I/O mode.
7. During a 0 to 1 transition, a one-shot drives the ports hard for two oscillator clock cycles. This
measurement reflects port in transition mode.
8. Ports 1, 2, 3, 5, 6 source transition current when being pulled down externally. Current reaches its
maximum at approximately 2V.
9. 0.45<Vin<V_CC. Not a high impedance input. This port is a weak address holding latch in Bus Mode.
Peak current occurs near the input transition point of the latch, approximately 2V.
10. 0.45<Vin<V_CC. RST=V_CC. This condition mimics operation of pins in I/O mode.
11. This is the current required from an external circuit to hold a logic low level on an I/O pin while the
corresponding port latch is set to 1. This is only the current required to hold the low level; transitions
from 1 to 0 on an I/O pin will also have to overcome the transition current.
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