MIC2560 Micrel Semiconductor, MIC2560 Datasheet - Page 6

• Manufacturer Part Number: MIC2560
• Description: PCMCIA Card Socket VCC and VPP Switching Matrix
• Manufacturer: Micrel Semiconductor

MIC2560
Applications Information
PCMCIA V
the MIC2560 voltage selector/switch IC. Four control bits
determine V
operate mode condition. V
(3.3V or 5V), V
When the V
device switches into “sleep” mode and draws only nano-
amperes of leakage current. An error flag falls low if the
output is improper, because of overtemperature or overcur-
rent faults. Full protection from hot switching is provided
which prevents feedback from the V
(from 12V to 5V, for example) by locking out the low voltage
switch until V
similarly protected against 5V to 3.3V shoot through.
The MIC2560 is a low-resistance power MOSFET switching
matrix that operates from the computer system main power
supply. Device logic power is obtained from V
internal MOSFET drive is obtained from the V
(usually +12V) during normal operation. If +12V is not
available, the MIC2560 automatically switches into “sus-
pend” mode, where V
higher switch resistance. Internal break-before-make switches
determine the output voltage and device mode.
Supply Bypassing
External capacitors are not required for operation. The
MIC2560 is a switch and has no stability problems. For best
results however, bypass V
with filter capacitors to improve output ripple. As all internal
device logic and voltage/current comparison functions are
powered from the V
the most critical, and may be necessary in some cases. In the
most stubborn layouts, up to 0.47 F may be necessary. Both
V
capacitors for noise reduction and electrostatic discharge
(ESD) damage prevention. Larger values of output capacitor
might create current spikes during transitions, requiring larger
bypass capacitors on the V
MIC2560
CC OUT
and V
CC
CC OUT
CC
PP OUT
and V
PP
high impedance condition is selected, the
PP OUT
, or a high impedance state are available.
CC3
PP
drops below V
CC OUT
and V
control is easily accomplished using
IN line, supply bypass of this line is
pins may have 0.01 F to 0.1 F
CC3
CC3
PP OUT
can be switched to 3.3V, but at
PP OUT
IN, V
IN, V
CC5
PP OUT
CC5
output voltages of V
CC
voltage and standby/
. The V
IN, and V
IN, and V
to the V
CC
PP
PP
PP
CC
output is
IN inputs
CC3
IN pins.
IN pin
inputs
and
CC
6
PCMCIA Implementation
The MIC2560 is designed for compatibility with the Personal
Computer Memory Card International Association’s (PCM-
CIA) Specification, revision 2.1 as well as the PC Card
Specification, (March 1995), including the CardBus option.
The Personal Computer Memory Card International Associa-
tion (PCMCIA) specification requires two V
PCMCIA slot. V
(EEPROM) memory cards. The two V
programmed to different voltages. Fully implementing PCM-
CIA specifications requires a MIC2560, a MIC2557 PCMCIA
V
full configuration, supporting both 5.0V and 3.3V V
tion.
PP
application with dual V
Figure 3. MIC2560 Typical PCMCIA memory card
Switching Matrix, and a controller. Figure 3 shows this
Controller
Card Slot
System
Supply
PCMCIA
Power
3.3V
12V
5V
PP
EN0
EN1
V PP IN V DD
is primarily used for programming Flash
MIC2557
V
V PP OUT
PP1
V CC
CC
and V
(5.0V or 3.3V) and separate
EN0
EN1
V CC5_EN
V CC3_EN
V PP IN
MIC2560
V CC3 IN
PP2.
PP
V CC5 IN
supply pins may be
PP
November 1999
supply pins per
V PP1
V PP2
V CC
CC
Card Slot
PCMCIA
opera-
Micrel