AT83EC5123 ATMEL Corporation, AT83EC5123 Datasheet - Page 56

• Manufacturer Part Number: AT83EC5123
• Description: (AT8xx512x) Smart Card Reader ICs
• Manufacturer: ATMEL Corporation

56
AT8xC5122/23
BOOST[1:0] bits beyond [0:0] level. If at least one of the two conditions are not met
(VCC < 3.6V or startup current > 30 mA), it will be necessary to increment the
BOOST[1:0] bits until the DC/DC converter is ready.
Incrementation of BOOST[1:0] bits increases at the same time the current overflow level
in the same proportion as the startup current. So once the DC/DC converter is ready it
advised to decrement the BOOST[1:0] bits to restore the overflow current to its normal
or desired value.
Table 56. DC/DC Converter Control Register - DCCKPS (S:BFh)
Reset Value = 0000 0000b
Number
MODE
5 - 4
3 - 0
Bit
7
7
6
Bit Mnemonic Description
DCCKPS[3:0]
BOOST[1:0]
OVFADJ
OVFADJ
MODE
6
BOOST1
Regulation mode
0 DC/DC converter (External Inductance required)
1 Voltage Regulator (No External inductance required but VCC >
CVCC+0.3V)
Current Overflow Adjustment on Smart Card terminal
0 normal: 100 mA average
1 normal + 20%
Maximum Startup Current drawn
from power supply
00 Normal: 30 mA average
01 Normal + 10%
10 Normal + 30%
11 Normal + 60%
DC/DC Clock Prescaler Value
0000 Division factor: 2 (reset value)
0001 Division factor: 3
0010 Division factor: 4
0011 Division factor: 5
0100 Division factor: 6
0101 Division factor: 8
0110 Division factor: 10
0111 Division factor: 12
1000 Division factor: 24
Other values reserved
5
BOOST0
4
DCCKPS3
3
DCCKPS2
Current Overflow Level on Smart
Card terminal
00 Normal = OVFADJ
01 Normal + 10%
10 Normal + 30%
11 Normal + 60%
2
DCCKPS1
1
4202B–SCR–07/03
DCCKPS0
0