MICREL MIC2563A-0BSM

MIC2563A
Micrel
MIC2563A
Dual Slot PCMCIA/CardBus Power Controller
Preliminary Information
General Description
Applications
The MIC2563A Dual Slot PCMCIA (Personal Computer
Memory Card International Association) and CardBus Power
Controller handles all PC Card slot power supply pins, both
VCC and VPP. The MIC2563A switches between the three VCC
voltages (0V, 3.3V and 5.0V) and the VPP voltages (OFF, 0V,
3.3V, 5V, or 12.0V) required by PC Cards. The MIC2563A
switches voltages from the system power supply to VCC and
VPP. Output voltage is selected by two digital inputs each and
output current ranges up to 1A for VCC and 250mA for VPP.
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•
•
•
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The MIC2563A provides power management capability controlled by the PC Card logic controller. Voltage rise and fall
times are well controlled. Medium current VPP and high
current VCC output switches are self-biasing: no +12V supply
is required for 3.3V or 5V output.
The MIC2563A is designed for efficient operation. In standby
(sleep) mode the device draws very little quiescent current,
typically 0.3µA. The device and PCMCIA port is protected by
current limiting and overtemperature shutdown. Full crossconduction lockout protects the system power supplies.
Dual Slot PC Card Power Supply Pin Voltage Switch
CardBus Slot Power Supply Control
Data Collection Systems
Machine Control Data Input Systems
Wireless Communications
Bar Code Data Collection Systems
Instrumentation Configuration/Datalogging
Docking Stations (portable and desktop)
Power Supply Management
Power Analog Switching
2
Features
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•
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Single Package Controls Two PC Card Slots
High Efficiency, Low Resistance Switches Require No
12V Bias Supply
No External Components Required
Output Current Limit and Overtemperature Shutdown
Ultra Low Power Consumption
Complete Dual Slot PC Card/CardBus VCC and VPP
Switch Matrix in a Single Package
Logic Compatible with Industry Standard PC Card Logic
Controllers
No Voltage Shoot-Through or Switching Transients
Break-Before-Make Switching
Digital Selection of VCC and VPP Voltages
Over 1A VCC Output Current for Each Section
Over 250mA VPP Output Current for Each Section
28-Pin SSOP Package
The MIC2563A is an improved version of the MIC2563,
offering lower ON-resistances and a VCC pulldown clamp in
the OFF mode. It is available in a 28-pin SSOP.
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Ordering Information
Typical Application
•
•
•
•
•
•
5V
(opt)
Part Number
Temperature Range
Package
MIC2563A-0BSM
–40°C to +85°C
28-pin SSOP
MIC2563A-1BSM
–40°C to +85°C
28-pin SSOP
System
Power 3.3V
Supply
12V
(opt)
VPPIN VCC3IN VCC5IN
(opt)
EN0
Note: see the logic table inside for a description of the differences
between the logic options
EN1
VCC5_EN
PCMCIA
Card Slot
Controller
VPP1
VPP2 PCMCIA
Card Slot
A
VCC
VCC3_EN
MIC2563
VPP1
EN0
EN1
VCC5_EN
VCC3_EN
1997
2-47
PCMCIA
VPP2 PCMCIA
Card Slot
Slot
Card
B
VCC
MIC2563A
Micrel
Absolute Maximum Ratings
(Notes 1 and 2)
Power Dissipation, TAMBIENT ≤ 25°C ...... Internally Limited
SSOP .............................................................. 800 mW
Derating Factors (To Ambient)
SSOP ............................................................. 4 mW/°C
Storage Temperature .............................. –65°C to +150°C
Operating Temperature (Die) ................................... 125°C
Lead Temperature (5 sec) ........................................ 260°C
Supply Voltage, VPP IN ...................................................... 15V
VCC3 IN ................................................................ 7.5V
VCC5 IN ................................................................ 7.5V
Logic Input Voltages ..................................... –0.3V to +10V
Output Current (each Output)
VPP OUT ............................ >200mA, Internally Limited
VCC OUT ...................................... >1A, Internally Limited
Pin Configuration
A VCC5 IN
A VCC OUT
A VCC5 IN
GND
A VCC5_EN
A VCC3_EN
A EN0
A EN1
B VPP IN
B VPP OUT
NC
B VCC OUT
B VCC3 IN
B VCC OUT
28
2
27
3
26
4
25
5
24
6
23
7
22
8
21
9
20
10
19
11
18
12
17
13
16
14
15
Logic Block Diagram
A VPP IN
(optional)
AVCC OUT
A VCC3 IN
A VCC OUT
NC
A VPP OUT
A VPP IN
B EN1
B EN0
B VCC3_EN
B VCC5_EN
GND
B VCC5 IN
B VCC OUT
B VCC5 IN
A EN1
A VPP OUT
A EN0
A VCC5_EN
MIC2563
Section A
Control
Logic
A VCC3_EN
A VCC OUT
A VCC3 IN
A VCC5 IN
28 Pin SSOP Package
ILimit / Thermal
Shut Down
Connect all pins with the same name together for
proper operation.
Gate Drive
Generator
B VPP IN
(optional)
B EN1
B VPP OUT
B EN0
B VCC5_EN
Control
Logic
MIC2563A-1 Redefined Pin Assignment
Function
VPP_VCC
VPP_PGM
MIC2563
Section B
B VCC3_EN
Pin Number
Slot A
Slot B
7
21
8
22
B VCC OUT
VCC3 IN
VCC5 IN
Some pin names for the MIC2563A-1 are different from the
MIC2563A-0. This table shows the differences. All other pin
names are identical to the MIC2563A-0 as shown in the Pin
Configuration, above.
2-48
ILimit / Thermal
Shut Down
Gate Drive
Generator
GND
1997
MIC2563A
Micrel
Electrical Characteristics:
(Over operating temperature range with VCC3 IN = 3.3V, VCC5 IN = 5.0V, VPP IN = 12V, unless
otherwise specified.)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
DIGITAL INPUTS
VIH
Logic 1 Input Voltage
2.2
7.5
V
VIL
Logic 0 Input Voltage
–0.3
0.8
V
IIN
Input Current
±1
µA
10
µA
0 V < VIN < 5.5V
VPP OUTPUT
IPP OUT
Hi-Z
High Impedance Output
Leakage Current
Shutdown Mode
0 ≤ VPP OUT ≤ 12V
1
IPPSC
Short Circuit Current Limit
VPP OUT = 0
RO
Switch Resistance
Select VPP OUT = 5V
Select VPP OUT = 3.3V
IPP OUT = –100mA (Sourcing)
1.8
3.3
2.5
5
Ω
RO
Switch Resistance,
Select VPP OUT = 12V
VPP IN = 12V
IPP OUT = –100 mA (Sourcing)
0.6
1
Ω
RO
Switch Resistance,
Select VPP OUT = 0V
Select VPP OUT = clamped to ground
IPP OUT = 50µA (Sinking)
2500
3900
Ω
5
10
70
50
50
250
µs
0.2
0.3
A
VPP SWITCHING TIME (See Figure 1)
t1
t2
t3
Output Turn-ON Delay
(Note 3)
VPP OUT = Hi-Z to 10% of 3.3V
VPP OUT = Hi-Z to 10% of 5V
VPP OUT = Hi-Z to 10% of 12V
t4
t5
t6
Output Rise Time
(Note 3)
VPP OUT = 10% to 90% of 3.3V
VPP OUT = 10% to 90% of 5V
VPP OUT = 10% to 90% of 12V
100
100
100
200
300
225
800
1000
800
µs
t7
t8
t9
t10
Output Transition Timing
(Note 3)
VPP OUT = 3.3V to 90% of 12V
VPP OUT = 5V to 90% of 12V
VPP OUT = 12V to 90% of 3.3V
VPP OUT = 12V to 90% of 5V
100
100
100
100
250
200
200
350
1000
800
800
1200
µs
t14
t15
t16
Output Turn-Off Delay Time
(Notes 3, 5)
VPP OUT = 3.3V to Hi-Z
VPP OUT = 5V to Hi-Z
VPP OUT = 12V to Hi-Z
200
200
200
1000
1000
1000
ns
t11
t12
t13
Output Turn-OFF Fall Time
(Note 3)
VPP OUT = 90% to 10% of 3.3V
VPP OUT = 90% to 10% of 5V
VPP OUT = 90% to 10% of 12V
50
50
300
1000
1000
2000
ns
1997
2-49
2
MIC2563A
Micrel
Electrical Characteristics (continued)
Symbol
Parameter
Conditions
Min
Typ
1
1.5
Max
Units
VCC OUTPUT
ICCSC
Short Circuit Current Limit
VCC OUT = 0
A
RO
Switch Resistance
Select VCC OUT = 3.3V
ICC OUT = –1A (Sourcing)
100
150
mΩ
Select VCC OUT = 5V
ICC OUT = –1A (Sourcing)
70
100
mΩ
Select VCC OUT = clamped to ground
ICC OUT = 0.1mA (Sinking)
500
3900
Ω
µs
VCC SWITCHING TIME (See Figure 2)
t1
Output Turn ON Delay Time
VCC OUT = 0V to 10% of 3.3V
300
1500
t2
(Note 4)
VCC OUT = 0V to 10% of 5.0V
750
3000
t3
Output Rise Time
(Note 4)
VCC OUT = 10% to 90% of 3.3V
200
700
2500
VCC OUT = 10% to 90% of 5V
200
1500
6000
VCC OUT = 3.3V
2.4
8
VCC OUT = 5V
2.8
8
t4
t7
Output Turn-Off Delay
(Notes 4, 5)
t8
t5
Output Fall Time
(Note 4)
µs
ms
µs
VCC OUT = 90% to 10% of 3.3V
100
240
1000
VCC OUT = 90% to 10% of 5.0V
100
600
2000
8
50
VCC OUT = 0V (Sleep Mode)
0.2
10
VCC3 IN Supply Current (3.3V)
VCC OUT = 5V or 3.3V, ICC OUT = 0
40
100
(Note 6)
VCC OUT = 0V (Sleep Mode)
0.1
10
VPP IN Supply Current (12V)
VPP OUT = 3.3V or 5V. IPP OUT = 0
0.3
4
(Note 7)
VPP OUT = Hi-Z, 0 or VPP
0.3
4
VCC5
Operating Input Voltage (5V)
VCC5 IN not required for operation
—
5.0
6
V
VCC3
Operating Input Voltage (3.3V)
(Note 6)
3.0
3.3
6
V
VPP IN
Operating Input Voltage (12V)
VPP IN not required for operation
(Note 8)
—
12.0
14.5
V
t6
POWER SUPPLY
ICC5
ICC3
IPP IN
VCC5 IN Supply Current (5V)
VCC OUT = 5V or 3.3V, ICC OUT = 0
2-50
µA
µA
µA
1997
MIC2563A
Micrel
Electrical Characteristics (continued)
Symbol
Parameter
Conditions
Min
Typ
Max
Units
THERMAL SHUTDOWN
Thermal Shutdown Temperature
TSD
NOTE 1:
NOTE 2:
Functional operation above the absolute maximum stress ratings is not implied.
Static-sensitive device. Store only in conductive containers. Handling personnel and equipment should be grounded to
prevent damage from static discharge.
RL = 100Ω connected to ground.
RL = 10Ω connected to ground.
Delay from commanding Hi Z or 0V to beginning slope. Does not apply to current limit or overtemperature shutdown
conditions.
The MIC2563A uses VCC3 IN for operation. For single 5V supply systems, connect 5V to both VCC3 IN and VCC5IN. See Applications Information for further details.
VPP IN is not required for operation.
VPP IN must be either high impedance or greater than or approximately equal to the highest voltage VCC in the system. For
example, if both 3.3V and 5V are connected to the MIC2563A, VPP IN must be either 5V, 12V, or high impedance.
NOTE 3:
NOTE 4:
NOTE 5:
NOTE 6:
NOTE 7:
NOTE 8:
A
VPP
Enable
°C
130
B
VPP to 3.3V
C
VPP to 12V
D
VPP to 3.3V
E
VPP
OFF
F
VPP to 5V
G
VPP to 12V
H
VPP to 5V
J
VPP OFF
K
VPP to 12V
VPP OFF
0
t13
t7
t8
t9
t10
t6
t16
12V
t3
VPP
Output
t2
t4
t15
t1
t11
t5
t12
5V
t14
3.3V
0
Figure 1. MIC2563A VPP Timing Diagram. VPP Enable is shown generically: refer to the timing tables (below). At
time “A” VPP = 3.3V is selected. At B, VPP is set to 12V. At C, VPP = 3.3V (from 12V). At D, VPP is disabled. At E, VPP is
programmed to 5V. At F, VPP is set to 12V. At G, VPP is programmed to 5V. At H, VPP is disabled. At J, VPP is set to
12V. And at K, VPP is again disabled. RL = 100Ω for all measurements. Load capacitance is negligible.
1997
2-51
2
MIC2563A
Micrel
A
VCC
Enable
B
C
VCC to 3.3V
D
VCC OFF
VCC to 5V
VCC OFF
0
t2
t1
t8
t6
t4
5V
t7
t3
t5
3.3V
VCC
Output
0
Figure 2. MIC2563A VCC Timing Diagram. VCC Enable is shown generically: refer to the timing tables (below) for
specific control logic input. At time A, VCC is programmed to 3.3V. At B, VCC is disabled. At C, VCC is programmed
to 5V. And at D, VCC is disabled. RL = 10Ω
MIC2563A-0 Control Logic Table
VCC5_EN
VCC3_EN
EN1
EN0
VCC OUT
VPP OUT
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
Clamped to Ground
Clamped to Ground
Clamped to Ground
Clamped to Ground
3.3
3.3
3.3
3.3
5
5
5
5
3.3
3.3
3.3
3.3
High Z
High Z
High Z
Clamped to Ground
High Z
3.3
12
Clamped to Ground
High Z
5
12
Clamped to Ground
High Z
3.3
5
Clamped to Ground
2-52
1997
MIC2563A
Micrel
MIC2563A-1 Control Logic (compatible with Cirrus Logic CL-PD6710 & PD672x-series
Controllers)
VCC5_EN
VCC3_EN
VPP_PGM
VPP_VCC
VCC OUT
VPP OUT
0
0
0
0
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
0
0
1
1
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
0
1
0
1
Clamped to Ground
Clamped to Ground
Clamped to Ground
Clamped to Ground
5
5
5
5
3.3
3.3
3.3
3.3
Clamped to Ground
High Z
High Z
High Z
Clamped to Ground
5
12
High Z
Clamped to Ground
3.3
12
High Z
1
1
1
1
1
1
1
1
0
0
1
1
0
1
0
1
Clamped to Ground
Clamped to Ground
Clamped to Ground
Clamped to Ground
Clamped to Ground
High Z
High Z
High Z
MIC2563A-2 Logic (Compatible with Databook Controllers)
Pin 5
Pin 6
Pin 7
VCCSEL0(1) VPPSEL0(1) VCCSEL2(3)
0
1
0
1
0
1
0
1
1
1
0
0
1
1
0
0
0
0
0
0
1
1
1
1
Pins 2 & 14
Pin 13
VCC OUT
VPP OUT
Clamped to Ground
3.3V
3.3V
3.3V
Clamped to Ground
5V
5V
5V
Clamped to Ground
3.3V
12V
Clamped to Ground
Clamped to Ground
5V
12V
Clamped to Ground
The Databook DB86184 PCMCIA controller requires two 100kΩ pull-down resistors from pins 5 and 7 to
ground and a 100kΩ pull-up resistor from pin 6 to +3.3V (or +5V). Connect MIC2560-2 pin 8 to ground.
1997
2-53
2
MIC2563A
Micrel
Applications Information
PC Card power control for two sockets is easily accomplished using the MIC2563A PC Card/CardBus Slot V
&
CC
V Power Controller IC. Four control bits per socket deterPP
mine V
and V
voltage and standby/operate
CC OUT
PP OUT
mode condition. V outputs of 3.3V and 5V at the maximum
CC
allowable PC Card current are supported. V
output
PP OUT
voltages of V
(3.3V or 5V), V , 0V, or a high impedance
CC
PP
state are available. When the V
clamped to ground condiCC
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
(from 5V to 3.3V, for example) by locking out the
CC OUT
low voltage switch until the initial switch’s gate voltage drops
below the desired lower V .
CC
The MIC2563A operates from the computer system main
power supply. Device logic and internal MOSFET drive is
generated internally by charge pump voltage multipliers
. Switching speeds are carefully conpowered from V
CC3 IN
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 VCC3 IN, VCC5 IN, and VPP IN
inputs with 1µF capacitors to improve output ripple. As all
internal device logic and comparison functions are powered
from the VCC3 IN line, the power supply quality of this line is
the most important, and a bypass capacitor may be necessary for some layouts. Both VCC OUT and VPP OUT pins may
use 0.01µF to 0.1µF 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 Association’s (PCMCIA) PC Card Specification, (March 1995), including the CardBus option.
When a memory card is initially inserted, it should receive
V
— either 3.3V ± 0.3V or 5.0V ±5%. The initial voltage is
CC
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 and if the card is designed for dual
PP
V . If the card is compatible with and desires a different V
CC
CC
level, the controller commands this change by disabling V ,
CC
waiting at least 100ms, and then re-enabling the other V
CC
voltage.
V
switches are turned ON and OFF slowly. If commanded
CC
to immediately switch from one V
to the other (without
CC
turning OFF and waiting 100ms first), enhancement of the
second switch begins after the first is OFF, realizing breakbefore-make protection. V switches are turned ON slowly
PP
and OFF quickly, which also prevents cross conduction.
If no card is inserted or the system is in sleep mode, the slot
logic controller outputs a (VCC3 IN, VCC5 IN) = (0,0) to the
MIC2563A, which shuts down VCC. This also places the
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 VCC3 IN. The high voltage bias is
generated by an internal charge pump quadrupler. Systems
without 3.3V may connect VCC3 IN to 5V. Input logic threshold voltages are compatible with common PC Card logic
controllers using either 3.3V or 5V supplies.
The PC Card Specification defines two VPP supply pins per
card slot. The two VPP supply pins may be programmed to
different voltages. VPP is primarily used for programming
FLASH memory cards. Implementing two independent VPP
voltages is easily accomplished with the MIC2563A and a
MIC2557 PCMCIA VPP Switching Matrix. Figure 3 shows this
full configuration, supporting independent VPP and both 5.0V
and 3.3V VCC operation. However, few logic controllers
support multiple VPP—most systems connect VPP1 to VPP2
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 VPP IN (nominally +12V) to VPP OUT. The low ON
resistance of the MIC2563A switch allows using a small
bypass capacitor on the VPP OUT pins, with the main filtering
action performed by a large filter capacitor on VPP IN (usually
the main power supply filter capacitor is sufficient). Using a
small-value capacitor such as 0.1µF on the output causes
little or no timing delays. The VPP OUT transition from VCC to
12.0V typically takes 250µs. After programming is completed, the controller outputs a (EN1, EN0) = (0,1) to the
MIC2563A, which then reduces VPP OUT to the VCC level.
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 VCC is available.
Output Current and Protection
MIC2563A output switches are capable of passing the maximum 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.
2-54
1997
MIC2563A
Micrel
5V
5V
(opt)
(opt)
System
Power 3.3V
Supply
System
Power 3.3V
Supply
12V
12V
(opt)
(opt)
VPP1
VPPIN VCC3IN VCC5IN
(opt)
EN0
VPPIN VCC3IN VCC5IN
(opt)
(opt)
A EN0
VPP2 PCMCIA
Card Slot
A
VCC
EN1
VCC5_EN
A EN1
A VCC5_EN
PCMCIA
Card Slot
Controller
VCC3_EN
MIC2563
PCMCIA
Card Slot
Controller
MIC2563
VPP1
B EN0
PCMCIA
VPP2 PCMCIA
Card Slot
Slot
Card
B
VCC
EN1
VCC5_EN
VPP2 PCMCIA
Card Slot
A
VCC
A VCC3_EN
VPP1
EN0
VPP1
B EN1
B VCC5_EN
PCMCIA
VPP2 PCMCIA
Card Slot
Slot
Card
B
VCC
B VCC3_EN
VCC3_EN
EN0
EN1
MIC2558
2
EN0
EN1
Figure 3. PC Card slot power control application with
dual VCC (5.0V or 3.3V) and separate VPP1 and VPP2.
Figure 4. Typical PC Card slot power control application
with dual VCC (5.0V or 3.3V). Note that VPP1 and VPP2 are
driven together.
5V
System
Power
Supply
12V
(opt)
VPPIN VCC3IN VCC5IN
(opt)
A EN0
A EN1
A VCC5_EN
PCMCIA
Card Slot
Controller
VPP1
VPP2 PCMCIA
Card Slot
A
VCC
A VCC3_EN
MIC2563
VPP1
B EN0
B EN1
B VCC5_EN
PCMCIA
VPP2 PCMCIA
Card Slot
Slot
Card
B
VCC
B VCC3_EN
Figure 5. PC Card slot power control application without a 3.3V VCC supply. Note that VCC3 IN and VCC5 IN lines are driven
together. The MIC2563A is powered from the VCC3 IN line. In this configuration, VCC OUT will be 5V when either VCC3 or VCC5
is enabled.
1997
2-55
MIC2563A
Micrel
RST#
VCC
20
SER_DATA
2
3
4
5
6
7
8
9
D
Q
D
Q
D
Q
D
Q
D
Q
D
Q
D
Q
D
Q
1 CLR
19
4
18
5
17
12
16
13
15
4
14
5
13
12
12
13
74x175
9 CLK
D
Q
D
Q
D
Q
D
Q
D
Q
D
Q
D
Q
D
Q
2
7
10
15
2
7
10
15
A_VPP_PGM (Pin 8)
A_VPP_VCC (Pin 7)
A_VCC5_EN (Pin 5)
A_VCC3_EN (Pin 6)
B_VPP_PGM (Pin 22)
B_VPP_VCC (Pin 21)
B_VCC3_EN (Pin 19)
B_VCC5_EN (Pin 20)
10
SER_CLK
11
74x574
1 CLR
1
9 CLK
74x175
SER_LATCH
Figure 6. Interfacing the MIC2563A with a serial-output data controller. Pinouts shown are for the MIC2563A-1
and a three-wire serial controller.
Serial Control
Figure 6 shows conversion from a three-wire serial interface,
such as used by the Cirrus Logic CL-PD6730, to the standard
eight-line parallel interface used by the MIC2563A-1. This
interface requires three common, low cost 7400-series logic
ICs:
Serial Control Adapter P.C. Board Layout
• 74x574 Octal D Flip-Flop
• 74x175 Quad Flip-Flop with Latches (two needed)
Either 3.3V or 5V logic devices may be used, depending upon
the control voltage employed by the slot logic controller. Pin
numbers in parenthesis refer to the MIC2563A-1BSM.
Gerber™ files for this P.C. board layout are available to Micrel
customers. Please contact Micrel directly.
Another serial-to-parallel solution for this application is the
74HC594, 8-bit shift register with output registers. This device contains the eight D flip-flops plus has latched outputs
suitable for this purpose.
Component Key
U1 ............. MIC2563
2-56
U2, U3 ...... 74x175
U4 ............. 74x574
1997