MIC2563A MICREL [Micrel Semiconductor], MIC2563A Datasheet - Page 8

• Manufacturer Part Number: MIC2563A
• Description: Dual Slot PCMCIA/CardBus Power Controller Preliminary Information
• Manufacturer: MICREL [Micrel Semiconductor]

MIC2563A
Applications Information
PC Card power control for two sockets is easily accom-
plished using the MIC2563A PC Card/CardBus Slot V
V
mine V
mode condition. V
allowable PC Card current are supported. V
voltages of V
state are available. When the V
tion is selected, the device switches into “sleep” mode and
draws only nanoamperes of leakage current. Full protection
from hot switching is provided which prevents feedback from
the V
low voltage switch until the initial switch’s gate voltage drops
below the desired lower V
The MIC2563A operates from the computer system main
power supply. Device logic and internal MOSFET drive is
generated internally by charge pump voltage multipliers
powered from V
trolled to prevent damage to sensitive loads and meet all PC
Card Specification timing requirements.
Supply Bypassing
External capacitors are not required for operation. The
MIC2563A is a switch and has no stability problems. For best
results however, bypass V
inputs with 1 F capacitors to improve output ripple. As all
internal device logic and comparison functions are powered
from the V
the most important, and a bypass capacitor may be neces-
sary for some layouts. Both V
use 0.01 F to 0.1 F capacitors for noise reduction and
electrostatic discharge (ESD) damage prevention.
PC Card Slot Implementation
The MIC2563A is designed for full compatibility with the
Personal Computer Memory Card International Associa-
tion’s (PCMCIA) PC Card Specification, (March 1995), in-
cluding the CardBus option.
When a memory card is initially inserted, it should receive
V
determined by a combination of mechanical socket “keys”
and voltage sense pins. The card sends a handshaking data
stream to the controller, which then determines whether or
not this card requires V
V
level, the controller commands this change by disabling V
waiting at least 100ms, and then re-enabling the other V
voltage.
V
to immediately switch from one V
turning OFF and waiting 100ms first), enhancement of the
second switch begins after the first is OFF, realizing break-
before-make protection. V
and OFF quickly, which also prevents cross conduction.
PP
CC
CC
CC
. If the card is compatible with and desires a different V
Power Controller IC. Four control bits per socket deter-
switches are turned ON and OFF slowly. If commanded
CC OUT
— either 3.3V 0.3V or 5.0V 5%. The initial voltage is
CC OUT
CC3
CC
(from 5V to 3.3V, for example) by locking out the
IN line, the power supply quality of this line is
and V
CC3 IN
(3.3V or 5V), V
CC
outputs of 3.3V and 5V at the maximum
PP OUT
. Switching speeds are carefully con-
PP
and if the card is designed for dual
CC
PP
CC3
CC OUT
.
switches are turned ON slowly
voltage and standby/operate
CC
PP
IN, V
, 0V, or a high impedance
clamped to ground condi-
CC
and V
CC5
to the other (without
PP OUT
IN, and V
PP OUT
pins may
output
PP
CC
CC
CC
CC
IN
&
,
2-54
If no card is inserted or the system is in sleep mode, the slot
logic controller outputs a (V
MIC2563A, which shuts down V
switch into a high impedance output shutdown (sleep) mode,
where current consumption drops to nearly zero, with only
tiny CMOS leakage currents flowing.
Internal device control logic and MOSFET drive and bias
voltage is powered from V
generated by an internal charge pump quadrupler. Systems
without 3.3V may connect V
old voltages are compatible with common PC Card logic
controllers using either 3.3V or 5V supplies.
The PC Card Specification defines two V
card slot. The two V
different voltages. V
FLASH memory cards. Implementing two independent V
voltages is easily accomplished with the MIC2563A and a
MIC2557 PCMCIA V
full configuration, supporting independent V
and 3.3V V
support multiple V
and the MIC2557 is not required. This circuit is shown in
Figure 4.
During Flash memory programming with standard (+12V)
Flash memories, the PC Card slot logic controller outputs a
(0 , 1) to the EN0, EN1 control pins of the MIC2563A, which
connects V
resistance of the MIC2563A switch allows using a small
bypass capacitor on the V
action performed by a large filter capacitor on V
the main power supply filter capacitor is sufficient). Using a
small-value capacitor such as 0.1 F on the output causes
little or no timing delays. The V
12.0V typically takes 250 s. After programming is com-
pleted, the controller outputs a (EN1, EN0) = (0,1) to the
MIC2563A, which then reduces V
Break-before-make switching action and controlled rise times
reduces switching transients and lowers maximum current
spikes through the switch.
Figure 5 shows MIC2563A configuration for situations where
only a single +5V V
Output Current and Protection
MIC2563A output switches are capable of passing the maxi-
mum current needed by any PC Card. The MIC2563A meets
or exceeds all PCMCIA specifications. For system and card
protection, output currents are internally limited. For full
system protection, long term (millisecond or longer) output
short circuits invoke overtemperature shutdown, protecting
the MIC2563A, the system power supplies, the card socket
pins, and the PC Card.
PP
CC
IN (nominally +12V) to V
operation. However, few logic controllers
PP
CC
PP
PP
—most systems connect V
PP
is available.
Switching Matrix. Figure 3 shows this
supply pins may be programmed to
is primarily used for programming
PP OUT
CC3
CC3
CC3
PP OUT
IN. The high voltage bias is
IN to 5V. Input logic thresh-
IN, V
pins, with the main filtering
CC
PP OUT
. This also places the
CC5
transition from V
PP OUT
PP
to the V
IN) = (0,0) to the
PP
supply pins per
and both 5.0V
PP
. The low ON
PP1
IN (usually
CC
to V
Micrel
CC
level.
1997
PP2
PP
to