73S8009CN Datasheet, PDF (27/30 Pages) Teridian Semiconductor Corporation – Combo ISO-7816 and USB Universal Smart Card Interface IC

DS_8009CN_026
Pull-up
Disable
To
circuit
Pull-down
Enable
VDD
VERY
WEAK
PFET
ESD
73S8009CN Data Sheet
PIN
ESD
VERY
WEAK
NFET
Note:
Pins CMDVCC%, CMDVCC#, CS, SC/USB have the pull-up enabled.
Pins RSTIN, CLKIN, PRES, EXT_RST have the pull-down enabled.
Pin OFF_ACK has a 100kΩ resistor connected to pin OFF_REQ internally.
Figure 19: General Input Circuit
VDD
Output
Disable
STRONG
PFET
ESD
PIN
Data
From
circuit
ESD
STRONG
NFET
100k ohm
To
OFF_ACK
pad
Notes:
Strong PFET or NFET is approximately 100Ω
Very strong PFET or NFET is approximately 50Ω
Medium strength PFET is approximately 1kΩ
Very weak PFET or NFET is approximately 1MΩ
The diodes represent ESD protection devices that will conduct current if forward biased.
Figure 20: OFF_REQ Interface Circuit
Rev. 1.4
27