CryptoCompanion

™ Chip

5277AS− CryptoCompanion −02/08

1.3.

Package, Pin Definition & IO

1.3.1. Pin Definition

1.3.1.1.

Vcc, Gnd

Power supply is 2.7 – 3.6V. Supply current less than 50mA.

CryptoCompanion will be available to accept commands 60ms after the later of Vcc rising above 2.7V or Reset being

driven high if CryptoCompanion is in a security delay then this interval is significantly longer.

During Power Up, Vcc must exhibit a monotonic ramp at a minimum rate of 50 mV/mS until Vcc has crossed the 2.7V

level. During Power Down, Vcc must exhibit a monotonic ramp at a minimum rate of 50 mV/mS once it has dropped

below the 2.5V boundary.

Vcc must be bypassed with high quality surface mount capacitors that are properly located on the board. Atmel

recommends two capacitors connected in parallel having a value of 1µF and 0.01µF. The capacitors should be

manufactured using X5R or X7R dielectric material. These capacitors should be connected to CryptoCompanion using

a total of no more than 1cm PC board traces. Atmel recommends the use of a ground plane and a trace length of less

than 0.5cm between the capacitors and the Vcc pin. Failure to follow these recommendations may result in improper

operation.

1.3.1.2.

SDA

Two wire interface data pin, 5V tolerant. Minimum data setup time = 0.1µs, and minimum data hold time = 0

µs min. The

system board must include an external pull-up resistor.

1.3.1.3.

SCL

0.6

µs. The system board must include an external pull-up resistor.

1.3.1.4.

Reset (RST)

This active low input will reset all states within CryptoCompanion. Honored regardless of the state of PowerDown.

1.3.1.5.

PowerDown (PDN)

When held low, the part operates normally. When held high the part will go to sleep and ignore all transitions on SDA

and SCL, power consumption will drop to less than 10uA. There is a 50ms delay between this pin falling and the first

transition on SDA or SCL that will be accepted by the chip.

1.3.2. Package

CryptoCompanion is packaged in an 8 lead SOIC package with the following pin definition:

Table 1.

8 lead SOIC package pin definition

Pin Number

Pin Name

1

Vcc

5

Gnd

7

SDA

8

SCL

4

RST

3

PDN

2,6

NC

Pins 2 & 6 are NC and should be connected to ground on the PC board.