Datasheet MAX1601EAI, MAX1604EAI Datasheet (Maxim)

19-1085; Rev 1; 10/96

Dual-Channel CardBus and PCMCIA

Power Switches with SMBus™ Serial Interface

________________General Description

The MAX1601/MAX1604 DC power-switching ICs con­tain a network of low-resistance MOSFET switches that
deliver selectable VCC and VPP voltages to two
CardBus or PC Card host sockets. Key features include
ultra-low-resistance switches, small packaging, soft­switching action, and compliance with PCMCIA specifi­cations for 3V/5V switching. 3.3V-only power switching
for fast, 32-bit CardBus applications is supported in two
ways: stiff, low-resistance 3.3V switches allow high 3.3V
load currents (up to 1A); and completely independent
internal charge pumps let the 3.3V switch operate nor­mally, even if the +5V and +12V supplies are discon­nected or turned off to conserve power. The internal
charge pumps are regulating types that draw reduced
input current when the VCC switches are static. Also,
power consumption is automatically reduced to 10µA
max when the switches are programmed to high-Z or
GND states over the serial interface, unlike other solu­tions that may require a separate shutdown-control
input.

Other key features include guaranteed specifications for
output current limit level, and guaranteed specifications
for output rise/fall times (in compliance with PCMCIA
specifications). Reliability is enhanced by thermal-over­load protection, accurate current limiting, an overcur­rent-fault flag output, undervoltage lockout, and extra
ESD protection at the VCC/VPP outputs. The SMBus ser­ial interface is flexible, and can tolerate logic input levels
in excess of the positive supply rail.

The MAX1604 and MAX1601 are identical, except
for the MAX1604’s VY switch, which has roughly three­times the on-resistance (typically 140mΩ).The
MAX1601/MAX1604 fit two complete CardBus/PCMCIA
switches into a space-saving, narrow (0.2in. or 5mm
wide) SSOP package.

________________________Applications

Desktop Computers Data Loggers
Notebook Computers Digital Cameras
Docking Stations Printers
Handy-Terminals PCMCIA Read/Write Drives

____________________________Features

♦ Supports Two CardBus Sockets
♦ 1A, 0.08Ω Max VY VCC Switch (MAX1601 only)

1A, 0.14Ω Max VX VCC Switch

♦ Soft Switching for Low Inrush Surge Current
♦ Overcurrent Protection
♦ Overcurrent/Thermal-Fault Flag Output
♦ Thermal Shutdown at T

= +150°C

j

♦ Independent Internal Charge Pumps
♦ Break-Before-Make Switching Action
♦ 10µA Max Standby Supply Current
♦ 5V and 12V Not Required for Low-R

DS(ON)

3.3V

Switching

♦ Complies with PCMCIA 3V/5V Switching

Specifications

♦ Super-Small, 28-Pin SSOP Package

(0.2in. or 5mm wide)

♦ System Management Bus (SMBus) Serial

Interface

_______________Ordering Information

PART

MAX1601EAI
MAX1604EAI

TEMP. RANGE PIN-PACKAGE

-40°C to +85°C

-40°C to +85°C

28 SSOP
28 SSOP

__________Simplified Block Diagram

12IN

SMBCLK

SMBDATA

SMBSUS

GND

12IN

VY
VY

VX
VX

VL

MAX1601/MAX1604

VDD

DECODE

LOGIC

ADDRESS

SELECT

OVERCURRENT

AND 

THERMAL

SHUTDOWN

VPPA

VCCA
VCCA

VCCA

SMBALERT

ADR
VPPB

MAX1601/MAX1604

Pin Configuration appears on last page.

SMBus is a trademark of Intel Corp.

________________________________________________________________

VY

VX

Maxim Integrated Products

VCCB
VCCB
VCCB

1

For free samples & the latest literature: http://www.maxim-ic.com, or phone [phone]

Dual-Channel CardBus and PCMCIA
Power Switches with SMBus™ Serial Interface

ABSOLUTE MAXIMUM RATINGS

Inputs/Outputs to GND

(VL, VX, VY, VCCA, VCCB) (Note 1)........................-0.3V, +6V

VPP Inputs/Outputs to GND

(12INA, 12INB, VPPA, VPPB) (Note 1)..................-0.3V, +15V

Inputs and Outputs to GND (SMBCLK, SMBDATA,

SMBSUS, SMBALERT) (Note 1)..............................-0.3V, +6V

ADR Input to GND ...........................................-0.3V, (VL + 0.3V)

VCCA, VCCB Output Current (Note 2).....................................4A

VPPA, VPPB Output Current (Note 2)...............................250mA

Note 1: There are no parasitic diodes between any of these pins, so there are no power-up sequencing restrictions (for example,

logic input signals can be applied even if all of the supply voltage inputs are grounded).

Note 2: VCC and VPP outputs are internally current-limited to safe values. See the

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

ELECTRICAL CHARACTERISTICS

MAX1601/MAX1604

(VL = VY = 3.3V, VX = 5V, 12INA = 12INB = 12V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

CONDITIONS

POWER-SUPPLY SECTION

Input Voltage Range

Undervoltage Lockout Threshold

VCC SWITCHES

On-Resistance, VY Switches

VX, VY or VL
12INA, 12INB
VL falling edge
12IN falling edge
12IN rising edge
VX, VY falling edge

VX or VY, all switches 0V or high-Z,
control inputs = 0V or VL, TA= +25°C

Any combination of VY switches on,
control inputs = 0V or VL, no VCC loads

Any combination of VX switches on,
control inputs = 0V or high-Z, no VCC loads

12INA tied to 12INB, all switches 0V or high-Z,
control inputs = 0V or VL, TA= +25°C

12INA tied to 12INB, VPPA and VPPB 12V switches on,
control inputs = 0V or VL, no VPP loads

All switches 0V or high-Z, control inputs = 0V or VL,
TA= +25°C

Any combination of switches on
When using VL as shutdown pin (Note 3)

VCCA or VCCB, VX = VY = 3V to 5.5V
12INA = 12INB = 0V to 13V,

VY = 3V, VX = 0V to 5.5V,
I

12INA = 12INB = 0V to 13V, VX = 4.5V, VY = 0V to 5.5V,
I

SWITCH

SWITCH

= 1A, TA= +25°C

= 1A, TA= +25°C

VCCA, VCCB Short Circuit to GND............................Continuous

VPPA, VPPB Short Circuit to GND..............................Continuous

Continuous Power Dissipation (T

SSOP (derate 9.52mW/°C above +70°C) ....................762mW

Operating Temperature Range

MAX1601EAI/MAX1604EAI .............................-40°C to +85°C

Storage Temperature Range.............................-65°C to +160°C

Lead Temperature (soldering, 10sec).............................+300°C

Electrical Characteristics

MAX1601
MAX1604

= +70°C)

A

table.

3.0 5.5
11 13

2.4 2.5 2.8

1.8 3.0

5810

1.4 2.5 2.8

1 µA12IN_ Standby Supply Current

0.06 0.08

0.14 0.24

UNITSMIN TYP MAXPARAMETER

V

V

µA1Standby Supply Current

µA20 100VY Quiescent Supply Current

µA20 100VX Quiescent Supply Current

µA15 10012IN_ Quiescent Supply Current

µA410VL Standby Supply Current
µA25 150VL Quiescent Supply Current

V/µs0.05VL Fall Rate

A01Operating Output Current Range

Ω

Ω0.10 0.14On-Resistance, VX Switches

2 _______________________________________________________________________________________

Dual-Channel CardBus and PCMCIA

Power Switches with SMBus™ Serial Interface

ELECTRICAL CHARACTERISTICS (continued)

(VL = VY = 3.3V, VX = 5V, 12INA = 12INB = 12V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

Output Propagation Delay
Plus Rise Time

Output Propagation Delay
Plus Fall Time

VPP SWITCHES

Output Propagation Delay
Plus Rise Time

Output Propagation Delay
Plus Fall Time

INTERFACE AND LOGIC SECTION

SMBALERT Signal Propagation
Delay

SMBALERT Output Low Voltage
SMBALERT Output Leakage Current

CONDITIONS

VCCA or VCCB A1.2 4.0Output Current Limit
VCCA or VCCB < 0.4V, programmed to 0V state mA20Output Sink Current

VCCA or VCCB forced to 0V, high-Z state,
TA= +25°C

VCCA or VCCB, 0V to VX or VY, CL= 30µF,
RL= 25Ω, 50% of input to 90% of output, TA= +25°C

VCCA or VCCB, 0V to VX or VY, CL= 1µF,
RL= open circuit, 10% to 90% points, TA= +25°C

VCCA or VCCB, VX or VY to 0V, CL= 30µF,
RL= open circuit, 50% of input to 10% of output,
TA= +25°C

VCCA or VCCB, VX or VY to 0V, CL= 1µF,
RL= 25Ω, 90% to 10% points

VPPA or VPPB
12IN = 11.6V, I
Programmed to VX (5V) or VY (3.3V), TA= +25°C
VPPA or VPPB, programmed to 12V
VPPA or VPPB < 0.4V, programmed to 0V state

VPPA or VPPB forced to 0V, high-Z state,
TA= +25°C

VPPA or VPPB, 0V to 12IN_, CL= 0.1µF,
50% of input to 90% of output, TA= +25°C

VPPA or VPPB, 0V to 12IN_, CL= 0.1µF,
10% to 90% points, TA= +25°C

VPPA or VPPB, 12IN_ to 0V, CL= 0.1µF,
50% of input to 10% of output, TA= +25°C

VPPA or VPPB, 12IN_ to 0V, CL= 0.1µF,
90% to 10% points

VCC_ or VPP_, load step to SMBALERT output,
50% point to 50% point (Note 3)

I

= 1mA, low state

SINK

V

SMBALERT

Hysteresis = +20°C (Note 4)

SMBSUS, SMBCLK, SMBDATA
SMBSUS, SMBCLK, SMBDATA

SMBDATA, I

= 5.5V, high state

SINK

= 100mA, TA= +25°C

SWITCH

= 4mA

100 800Output Rise Time

2.2

UNITSMIN TYP MAXPARAMETER

MAX1601/MAX1604

µA10Output Leakage Current

ms210

µs100 1200Output Rise Time

ms60 100

ms6Output Fall Time

mA0 120Operating Output Current Range

Ω0.70 1On-Resistance, 12V Switches
Ω13On-Resistance, VPP = VCC Switches

mA130 200 260Output Current Limit
mA10Output Sink Current

µA10Output Leakage Current

ms1.2 30

µs

ms960

ms1Output Fall Time

µs3

V0.4

µA-0.1 0.1
°C150Thermal Shutdown Threshold

V0.8Logic Input Low Voltage
VLogic Input High Voltage

V0.4Logic Output Low Voltage

_______________________________________________________________________________________ 3

Dual-Channel CardBus and PCMCIA
Power Switches with SMBus™ Serial Interface

ELECTRICAL CHARACTERISTICS (continued)

(VL = VY = 3.3V, VX = 5V, 12INA = 12INB = 12V, TA= 0°C to +85°C, unless otherwise noted. Typical values are at TA= +25°C.)

PARAMETER MIN TYP MAX UNITS

SMB Input Capacitance 5 pF
SMBCLK Clock Frequency DC 100 kHz
SMBCLK Clock Low Time 4.7 µs
SMBCLK Clock High Time 4 µst

SMB Repeated Start-Condition
Setup Time

SMB Start-Condition Hold Time 4 µs
SMB Stop-Condition Setup Time 4 µs

SMB Data Valid to SMBCLK Rising­Edge Time

SMB Data Hold Time 0
Bus Free Time 4.7 µs

MAX1601/MAX1604

ADR Input Low Voltage 0.6 V
ADR Input High Voltage 1.5 V
Logic Input Bias Current -1 1 µA

SCL Fall to SDA Valid
(Master Clocking-In Data)

Start-Condition Setup

SMBSUS, SMBCLK, SMBDATA
SMBus spec = 10kHz min
t

10% to 10% points

LOW

90% to 90% points

HIGH

t

90% to 90% points

SU:STA

t
t

t
10% of SMBCLK

t
t

ADR, SMBSUS, SMBCLK, SMBDATA

10% of SMBDATA to 90% of SMBCLK

HD:STA

90% of SMBCLK to 10% of SMBDATA

SU:STO

10% or 90% of SMBDATA to

SU:DAT

(Note 5)

HD:DAT

between start and stop conditions

BUF

CONDITIONS

250 ns

500 ns

100 1000 ns

4.7 µs

ns

Note 3: Not production tested.
Note 4: Thermal limit not active in standby state (all switches programmed to GND or high-Z state).
Note 5: A transition must internally provide at least a hold time in order to bridge the undefined region (300ns max) of the falling

edge of SMBCLK.

4 _______________________________________________________________________________________

Dual-Channel CardBus and PCMCIA

Power Switches with SMBus™ Serial Interface

ELECTRICAL CHARACTERISTICS

(VL = VY = 3.3V, VX = 5V, 12INA = 12INB = 12V, TA= -40°C to +85°C, unless otherwise noted.)

CONDITIONS

POWER-SUPPLY SECTION

Input Voltage Range

Undervoltage Lockout Threshold

VX Quiescent Supply Current

INTERFACE AND LOGIC SECTION

SMBALERT Output Low Voltage

Logic Input High Voltage
Logic Output Low Voltage
ADR Input Low Voltage
ADR Input High Voltage

VX, VY or VL
12INA, 12INB
VL falling edge, hysteresis = 1%
12IN falling edge
12IN rising edge
VX, VY falling edge

VX or VY, all switches 0V or high-Z,
control inputs = 0V or VL

Any combination of VY switches on,
control inputs = 0V or VL, no VCC loads

Any combination of VX switches on,
control inputs = 0V or high-Z, no VCC loads

12INA tied to 12INB, all switches 0V or high-Z,
control inputs = 0V or VL

12INA tied to 12INB, VPPA and VPPB 12V switches on,
control inputs = 0V or VL, no VPP loads

All switches 0V or high-Z, control inputs = 0V or VL
Any combination of switches on

I

= 1mA, low state

SINK

SMBCLK, SMBDATA, SMBSUS
SMBCLK, SMBDATA, SMBSUS
SMBDATA, I

SINK

= 4mA

UNITSMIN TYP MAXPARAMETER

3.0 5.5
11 13

2.3 2.9

1.8

510

1.4 2.9

15

2.2

0.4

0.6

1.5

V

V

µA15Standby Supply Current

µA100VY Quiescent Supply Current

µA100

µA12IN_ Standby Supply Current

µA10012IN_ Quiescent Supply Current

µA15VL Standby Supply Current
µA150VL Quiescent Supply Current

V0.4
V0.8Logic Input Low Voltage

V
V
V
V

MAX1601/MAX1604

_______________________________________________________________________________________ 5

Dual-Channel CardBus and PCMCIA
Power Switches with SMBus™ Serial Interface

__________________________________________Typical Operating Characteristics

(VL = VY = 3.3V, VX = 5V, 12IN, TA = +25°C, unless otherwise noted.)

VCC_ SWITCHING (RISE)

6
4

VCC_

(V)

2
0

INPUT

(V)

5
0

200µs/div

CL = 30µF, RL = 25Ω

CONTROL

MAX1601/MAX1604

VCC_ SWITCHING (FALL)

6
4

VCC_

(V)

2
0

INPUT

(V)

5
0

CONTROL

MAX1601/4 TOC-01

MAX1601/4 TOC-03

VCC_

(V)

CONTROL

INPUT

(V)

VCC_

(V)

CONTROL

INPUT

(V)

3
2
1

0
5
0

CL = 1µF, RL = ∞

6
4
2

0
5
0

VCC_ SWITCHING (RISE)

MAX1601/4 TOC-02

500µs/div

VCC_ SWITCHING (FALL)

MAX1601/4 TOC-04

VPP_

(V)

CONTROL

INPUT

(V)

CL = 33µF, RL = ∞

15
10

5
0

5
0

CL = 0.1µF, RL = ∞

10ms/div

VPP_ SWITCHING (RISE)

200µs/div

MAX1601/4 TOC-05

VPP_

(V)

CONTROL

INPUT

(V)

CL = 1µF, RL = 25Ω

15
10

5
0

5
0

CL = 0.1µF, RL = ∞



VPP_ SWITCHING (FALL)

10ms/div

2ms/div

6 _______________________________________________________________________________________

MAX1601/4 TOC-06

Dual-Channel CardBus and PCMCIA

Power Switches with SMBus™ Serial Interface

_____________________________Typical Operating Characteristics (continued)

(VL = VY = 3.3V, VX = 5V, 12IN, TA = +25°C, unless otherwise noted.)

INPUT CURRENT (VCC OUTPUT SHORTED)

2.0

1.5

1.0

0.5
0

1ms/div

INPUT CURRENT (VPP OUTPUT SHORTED)

10

5
0

300
200

100

0

MAX1601/4 TOC-09

MAX1601/4 TOC-11

VCC_

(V)

VPP_

(V)

VCC_ CURRENT LIMITING

4
2
0

CL = 1µF, RESISTIVE OVERLOAD, RL = 1Ω

VPP_ CURRENT LIMITING

10

5
0

2ms/div

MAX1601/4 TOC-08

MAX1601/4 TOC-10

I

VY

(A)

VPP_

(V)

I

12IN_

(mA)





MAX1601/MAX1604

CL = 1µF, RL = 50Ω

2ms/div

RL = 0.1Ω

100µs/div

VCC_ SHUTDOWN RESPONSE

4
VL
(V)

VCC_

(V)

2

0



4

2

0

100µs/div

CIRCUIT OF FIGURE 2

MAX1601/4 TOC-12

_______________________________________________________________________________________

7

Dual-Channel CardBus and PCMCIA
Power Switches with SMBus™ Serial Interface

_____________________________Typical Operating Characteristics (continued)

(VL = VY = 3.3V, VX = 5V, 12IN, TA = +25°C, unless otherwise noted.)

VX ON-RESISTANCE 

vs. VCC_ LOAD CURRENT

110
105
100

95
90

(mΩ)

85

ON

80

VX R

75
70
65

MAX1601/MAX1604

60

200

0 1000

400 600 800

VCC_ LOAD CURRENT (mA)

TA = +85°C

TA = +25°C

TA = -40°C

MAX1601/4 TOC-13

(mΩ)

ON

VY R



12IN_ ON-RESISTANCE vs. CURRENT

725
720
715
710

(mΩ)

ON

705
700

12IN R

695
690
685

20 40 60 80

0 100 120 140

CURRENT (mA)

VY ON-RESISTANCE vs. CURRENT

MAX1601

80
75
70
65
60
55
50
45
40
35
30

200 400 600 800

0 1000

CURRENT (mA)

TA = +85°C

TA = +25°C

TA = -40°C

12IN_ ON-RESISTANCE vs. TEMPERATURE

950

VPPA

VPPB

MAX1601/4 TOC-15

900
850
800

(mΩ)

ON

750
700

12IN R

650
600
550

-40 60 80 100

165
160

MAX1601/4 TOC-14

155
150
145

(mΩ)

140

ON

135

VY R

130
125
120
115



-20 0 20 40
TEMPERATURE (°C)

VY ON-RESISTANCE vs. CURRENT

MAX1604

TA = +85°C

TA = +25°C

TA = -40°C

0 1000

200 400 600 800

CURRENT (mA)

MAX1601/4 TOC-16

MAX1600/3 TOC-20

VX, VY SUPPLY CURRENT

vs. INPUT VOLTAGE

0.9

0.8

0.7

0.6

0.5

0.4

0.3

0.2

VX, VY SUPPLY CURRENT (µA)

0.1
0

1234

056

INPUT VOLTAGE (V)

VX

VY

MAX1601/4 TOC-17

12IN SUPPLY CURRENT (µA)

7

6

5

4
3

2

1

0

12IN SUPPLY CURRENT

vs. INPUT VOLTAGE

70

60

MAX1601/4 TOC-18

50

40
30

20

VL SUPPLY CURRENT (µA)

10

0

01012

2468

INPUT VOLTAGE (V)

056

VL SUPPLY CURRENT

vs. VL INPUT VOLTAGE

VX = VY = 0V
12IN

1234

INPUT VOLTAGE (V)

8 _______________________________________________________________________________________

NORMAL
OPERATION

SHUTDOWN

MAX1601/4 TOC-19

Dual-Channel CardBus and PCMCIA

Power Switches with SMBus™ Serial Interface

______________________________________________________________Pin Description

PIN

1, 25 GND Ground

2, 3,

26, 27

4 12INA +12V Supply Voltage Input, internally connects to channel A VPP switch. Tie to VPPA if not used.
5 VPPA Channel A VPP Output

6, 8, 10 VX

7, 22, 24 VCCA Channel A VCC Outputs
9, 18, 20 VCCB Channel B VCC Outputs

11 VPPB Channel B VPP Output
12 12INB +12V Supply Voltage Input, internally connects to channel B VPP switch. Tie to VPPB if not used.
13 ADR Address Input, sets SMBus address location. See Table 1 for address selection.

14

15 SMBCLK SMBus Clock Input
16 SMBDATA SMBus Data Input/Output, open drain

17

19, 21, 23 VY

28 VL

NAME FUNCTION

N.C. No internal connection

VX Supply-Voltage Inputs. VX pins must be connected together. Input range is 3V to 5.5V. VX is
normally connected to 5V.

SMBus Suspend-Mode Control Input. The device will execute commands previously stored in

SMBSUS

SMBALERT

the normal-mode register if SMBSUS is high, or will execute commands previously stored in the
suspend-mode register if SMBSUS is low.

Fault-Detection Interrupt Output. SMBALERT goes low if either channel VCC or VPP switch is
current limiting or undervoltage lockout, or if the thermal protection circuit is activated.
SMBALERT is an open-drain output that requires an external pull-up resistor.

VY Supply-Voltage Inputs. VY pins must be connected together. Input range is 3V to 5.5V. VY is
normally connected to 3V.

Logic Supply-Voltage Inputs. Connect to the +3.3V or +5V host system supply. VL can be sup­plied via the output of a CMOS-logic gate to produce an overriding shutdown. When used as a
shutdown input, VL should have a 1kΩ series resistor with a 0.1µF capacitor to ground (Figure 2).
Note that VL must be greater than undervoltage lockout for any switches to be turned on.

MAX1601/MAX1604

_______________________________________________________________________________________ 9

Dual-Channel CardBus and PCMCIA
Power Switches with SMBus™ Serial Interface

VB12

12IN

VY

MAX1601/MAX1604

VY

VX

VX



CHARGE 

PUMP

VB3

CHARGE

PUMP

VB5

CHARGE

PUMP

0.08Ω

0.14Ω

*

CURRENT

LIMIT

CURRENT

LIMIT

CURRENT

LIMIT

1/2 MAX1601/MAX1604

3Ω

VPPA

40Ω

VCCA

VCCA

VCCA

20Ω

SMBCLK

SMBDATA

SMBSUS

ADR

SMB

VDD

VL

SHDN

THERMAL

SHUTDOWN

*0.24Ω FOR THE MAX1604

Figure 1. Functional Diagram (one channel of two)

10 ______________________________________________________________________________________

SMBALERT

GND

Dual-Channel CardBus and PCMCIA

Power Switches with SMBus™ Serial Interface

_______________Detailed Description

The MAX1601/MAX1604 power-switching ICs contain a
network of low-resistance MOSFET switches that deliver
selectable VCC and VPP voltages to two Cardbus or
PC Card host sockets. The MAX1601/MAX1604 differ
only in the VY switch on-resistance. Figure 1 is the
detailed block diagram.

The power-input pins (VY, VX, 12IN_) are completely
independent. Low inrush current is guaranteed by con­trolled switch rise times. VCC’s 100µs minimum output
rise time is 100% tested with a 1µF capacitive load, and
VPP’s 1ms minimum rise time is guaranteed with a 0.1µF
load. These respective capacitive loads are chosen as
worst-case card-insertion parameters. The internal
switching control allows VCC and VPP rise times to be
controlled, and makes them nearly independent of resis­tive and capacitive loads (see rise-time photos in the

Typical Operating Characteristics

function of loading, and are compensated by internal
circuitry.

Power savings is automatic: internal charge pumps draw
very low current when the VCC switches are static.
Standby mode reduces switch supply current to 1µA.
Driving the VL pin low with an external logic gate (master
shutdown) reduces total supply current to1µA (Figure 2).

The MAX1601/MAX1604 have three operating modes:
normal, standby, and shutdown. Normal mode supplies
the selected outputs with their appropriate supply volt­ages. Standby mode places all switches at ground, high
impedance, or a combination of the two. Shutdown mode
turns all switches off, and puts the VCC and VPP outputs
into a high-impedance state. Pull VL low to enter shutdown
mode. To ensure a 0.05V/µs fall rate on VL, use a 1kΩ
series resistor and a 0.1µF capacitor to ground (Figure 2).

Overcurrent Protection

Peak detecting circuitry protects both the VCC and
VPP switches against overcurrent conditions. When
current through any switch exceeds the internal current
limit (4A for VCC switches and 200mA for VPP switch­es), the switch turns off briefly, then turns on again at
the controlled rise rate. If the overcurrent condition
lasts more than 2µs, the SMBALERT output latches

). Fall times are a

Operating Modes

3.3V

VY

MAX1601
MAX1604

VPPA
VCCA

TO
SOCKETS
A AND B

VPPB

VCCB

MASTER

SHUTDOWN

74HC04

Figure 2. Master Shutdown Circuit

1k

0.1µF

VL

low. A continuous short-circuit condition results in a
pulsed output current until thermal shutdown is
reached. SMBALERT is open-drain and requires an
external pull-up resistor.

Thermal Shutdown

If the IC junction temperature rises above +150°C, the
thermal shutdown circuitry opens all switches, including
the GND switches, and SMBALERT is pulled low. When
the temperature falls below +130°C, the switches turn
on again at the controlled rise rate. If the overcurrent
condition remains, the part cycles between thermal
shutdown and overcurrent.

Undervoltage Lockout

If the VX or VY switch input voltage drops below 1.5V,
the associated switch turns off and SMBALERT goes
low. For example, if VY is 3.3V and VX is 0V, and if the
interface controller selects VY, the VCCA output will be

3.3V. If VX is selected, VCCA changes to a high-imped­ance output and SMBALERT goes low.

When a voltage is initially applied to 12IN_, it must be
greater than 8V to allow the switch to operate.
Operation continues until the voltage falls below 2V (the
VPP output is high impedance).

When VL drops to less than 2.3V, all switches are
turned off and the VCC and VPP outputs are high
impedance.

MAX1601/MAX1604

______________________________________________________________________________________ 11

Dual-Channel CardBus and PCMCIA
Power Switches with SMBus™ Serial Interface

______SMBus™ Interface Operation

The SMBus serial interface is a two-wire interface with
multi-mastering capability, intended to control low­speed peripheral devices in low-power portable equip­ment applications. SMBus is similar to I2C™ and
AccessBus, but has slightly different logic threshold
voltage levels, different fixed addresses, and a sus­pend-mode register capability. To obtain a complete
set of specifications on the SMBus interface, call Intel at
[phone] and ask for product code SBS5220.

SMBus Addressing

These dual-channel PC Card switch devices respond to
two of four different addresses, depending on the state
of the ADR address pin. Normal writing to the device is
done by transmitting one of four addresses, followed by
a single data byte, to program the channel selected.
Write transmissions to the interrupt pointer address are
not supported by these devices. Reading from the

MAX1601/MAX1604

device is done by transmitting one of two addresses cor-

Table 1. SMBus Addressing

SMB

ADDRESS

0001100 Don’t care N/A Interrupt Pointer
1010000 Grounded Channel A Channel A/B faults
1010001 Grounded Channel B Channel A/B faults
1010010 Tied to VL Channel A Channel A/B faults
1010011 Tied to VL Channel B Channel A/B faults

ADR PIN

WRITE

FUNCTION

READ FUNCTION

responding to either the A channel address (which will
provide data about faults for both A and B channels) or
to the interrupt pointer address (discussed later).

The normal start condition consists of a high-to-low
transition on SMBDATA while SMBCLK is high. The
7-bit address is followed by a bit that designates a read
or write operation: high = read, low = write. If the 7-bit
address matches one of the supported function
addresses, the IC issues an acknowledge pulse by
pulling the SMBDATA line low. If the address is not
valid, the IC stays off of the bus and ignores any data
on the bus until a new start condition is detected. Once
the IC receives a valid address that includes a write bit,
it expects to receive one additional byte of data. If a
stop condition or new start condition is detected before
a complete byte of data is clocked in, the IC interprets
this as an error and all of the data is rejected and lost.
SMBDATA and SMBCLK are Schmitt triggered and can
accommodate slower edges. However, rising edges
should still be faster than 1µs, and falling edges should
be faster than 300ns.

SMBus Write Operations

If the IC receives a valid address immediately followed
by a write bit, the IC becomes a slave receiver. The
slave IC generates a first acknowledge after the
address and write bit, and a second acknowledge after
the command byte. A stop condition following the com­mand (data) byte causes immediate execution of the
command, unless the data included a low SUS/OP bit.
If the data included a low SUS/OP bit, the command is
stored in the suspend-mode register and is executed
only when the SMBSUS pin is pulled low (Figure 3).

Table 2. Command Format for Channel A Write Operations (address 1010000 or 1010010)

FUNCTIONPOR STATENAMEBIT

0OP/SUS7 (MSB)

I2C is a trademark of Philips Corp.
SMBus is a trademark of Intel Corp.

12 ______________________________________________________________________________________

Operate/suspend bit. Selects which latch receives data: high = operation,
low = suspend.

Turns on VCCA when high, pulls VCCA to GND when low.0VCCAON6
If VCCA is on, a high connects VY to VCCA, and a low connects VX to VCCA.0VCCA3/55
Puts VCCA in a high-impedance state when high. Overrides VCCAON.0VCCAHIZ4
Turns on VPPA when high, pulls VPPA to GND when low.0VPPAON3
If VPPA is on, a high connects VPPA to 12INA, and a low connects VPPA to VCCA.0VPPAPGM2
Puts VPPA in a high-impedance state when high. Overrides VPPAON.0VPPAHIZ1
Masks fault interrupts from both channel A and channel B when high.0MASKFLT0 (LSB)

Dual-Channel CardBus and PCMCIA

Power Switches with SMBus™ Serial Interface

Table 3. Command Format for Channel B Write Operations (address 1010001 or 1010011)

BIT NAME POR STATE FUNCTION

7 (MSB) OP/SUS 0

6 VCCBON 0 Turns on VCCB when high, pulls VCCB to GND when low.
5 VCCB3/5 0 If VCCB is on, a high connects VY to VCCB, and a low connects VX to VCCB.
4 VCCBHIZ 0 Puts VCCB in a high-impedance state when high. Overrides VCCBON.
3 VPPBON 0 Turns on VPPB when high, pulls VPPB to GND when low.
2 VPPBPGM 0 If VPPB is on, a high connects VPPB to 12INB, and a low connects VPPB to VCCB.
1 VPPBHIZ 0 Puts VPPB in a high-impedance state when high. Overrides VPPBON.

0 (LSB) RFU 0 Reserved for future use.

Operate/suspend bit. Selects which latch receives data: high = operation,
low = suspend.

Table 4. Read Format for Interrupt Pointer Address (0001100)

BIT NAME POR STATE FUNCTION

7 (MSB) ADD7 0

6 ADD6 0
5 ADD5 0
4 ADD4 0
3 ADD3 0
2 ADD2 0
1 ADD1 0

0 (LSB) ADD0 0

ADD7 to ADD1 provide a return address for any interrupt query. For these devices, the
return addresses are:
1010000 = Channel A, ADD = low
1010001 = Channel B, ADD = low
1010010 = Channel A, ADD = high
1010011 = Channel B, ADD = high

MAX1601/MAX1604

Table 5. Read Format for Power Switch Address (1010000 or 1010010)

BIT NAME POR STATE FUNCTION

7 (MSB) CATFAULT 0 Indicates catastrophic (thermal or undervoltage lockout) fault when high.

6 FAULT1 0 Indicates VCCA overcurrent/undervoltage lockout when high.
5 FAULT2 0 Indicates VPPA overcurrent/undervoltage lockout when high.
4 FAULT3 0 Indicates VCCB overcurrent/undervoltage lockout when high.
3 FAULT4 0 Indicates VPPB overcurrent/undervoltage lockout when high.
2 SIG/DUAL 0 Indicates dual part (single-channel devices would read 1).
1 RFU 0 Reserved for future use.

0 (LSB) RFU 0 Reserved for future use.

______________________________________________________________________________________ 13

LATCHED?

Y
Y
Y
Y

Y
N
N
N

Dual-Channel CardBus and PCMCIA
Power Switches with SMBus™ Serial Interface

AB CD

t

LOWtHIGH

SMBCLK

SMBDATA

t

t

HD:STA

SU:STA

A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE
E = SLAVE PULLS SMBDATA LINE LOW

t

SU:DAT

F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO SLAVE (OP/SUS BIT)
H = LSB OF DATA CLOCKED INTO SLAVE
I = SLAVE PULLS SMBDATA LINE LOW


MAX1601/MAX1604

Figure 3. SMBus Write Timing Diagram

SMBus Read Operations

If the IC receives a valid address that includes a read
bit, the IC becomes a slave transmitter. After receiving
the address data, the IC generates an acknowledge
during the acknowledge clock pulse and drives the
SMBDATA line in sync with SMBCLK. The SMB proto­col requires that the master end the read transmission
by not acknowledging during the acknowledge bit of
SMBCLK. These PC Card ICs support the repeated
start-condition method for changing data-transfer direc­tion; that is, a write transmission followed by a repeated
start instead of a stop condition prepares the IC for
data reading (Figure 4).

SMBus Interrupts

These PC Card power-switch ICs are slave devices
only, and never initiate communications except by
asserting an interrupt (by pulling SMBALERT low).
Interrupts are generated only for reporting fault condi­tions, including overcurrent at VCCA, VCCB, VPPA, or
VPPB, undervoltage lockout, and IC thermal overload. If
an interrupt occurs, it can be an indication of impend­ing system failure. The host system can react by going
into suspend mode or taking other action. It can come
back later to interrogate the IC via the interrupt pointer
to determine status or perform corrective action (such
as disabling the appropriate power switch that might
be connected to a shorted PC card). The fastest
method for turning off the switches in response to a

E

FG H

t

HD:DAT

I

J

J = ACKNOWLEDGE CLOCKED INTO MASTER
K = ACKNOWLEDGE CLOCK PULSE
L = STOP CONDITION, DATA EXECUTED BY SLAVE
M = NEW START CONDITION

K

t

SU:STO

fault condition is to cycle the voltage on VL in order to
generate a power-on reset (which clears all of the
SMBus registers). Note that the SMBus registers retain
their data even if the main VX/VY supplies are turned
off, provided that VL remains powered.

When a fault occurs, SMBALERT is immediately assert­ed and latched low. If the fault is momentary and disap­pears before the IC is serviced, the data is still latched
in the interrupt pointer and SMBALERT remains assert­ed. Normally, the master (host system or PCMCIA digi­tal controller) now sends out the interrupt pointer
address (00011000) followed by a read bit. SMBALERT
is cleared and the PC Card IC responds by putting out
its address on the bus. If the fault persists, SMBALERT
is re-asserted, but the data in the fault registers is not
reloaded. The data in the fault latches only reflects the
first time SMBALERT is asserted.

When the part enters operating mode, a false interrupt
flag may be issued. The user needs to send the inter­rupt address to clear the false interrupt.

Normally, the master sends out the appropriate PC Card
switch address on the bus, followed by a read bit. The
data in the fault registers is then clocked out onto the
bus (which also clears the fault registers). If the fault
persists, the fault bits and SMBALERT are latched
again.

M

L

t

BUF

14 ______________________________________________________________________________________

Dual-Channel CardBus and PCMCIA

Power Switches with SMBus™ Serial Interface

SMBCLK

SMBDATA

AB CD

t

t

HIGH

LOW

FG H

E

I

J

MAX1601/MAX1604

K

t

SU:STAtHD:STA

A = START CONDITION
B = MSB OF ADDRESS CLOCKED INTO SLAVE
C = LSB OF ADDRESS CLOCKED INTO SLAVE
D = R/W BIT CLOCKED INTO SLAVE


Figure 4. SMBus Read Timing Diagram

t

SU:DAT

E = SLAVE PULLS SMBDATA LINE LOW
F = ACKNOWLEDGE BIT CLOCKED INTO MASTER
G = MSB OF DATA CLOCKED INTO MASTER
H = LSB OF DATA CLOCKED INTO MASTER


The interrupt pointer address provides quick fault iden­tification for simple slave devices that lack the complex,
expensive logic needed to be a bus master. The host
can read the interrupt pointer to determine which slave
device generated an SMBALERT interrupt signal. The
interrupt pointer address can activate several different
slave devices simultaneously, similar to an I2C general
call. Any slave device that generated an interrupt
attempts to identify itself by putting its own address on
the bus during the first read byte. If more than one slave
attempts to respond, bus arbitration rules apply and the
device with the lower address code wins. The losing
device won’t generate an acknowledge and will contin­ue to hold the SMBALERT line low until serviced, which
implies that the host interrupt input must be level
sensitive.

__________Applications Information

t

t

SU:STO

BUF

I = ACKNOWLEDGE CLOCK PULSE
J = STOP CONDITION
K = NEW START CONDITION

Changing SMBCLK and SMBDATA

Simultaneously

When clocking data into the MAX1601/MAX1604, SMB­DATA must not fall before SMBCLK. Otherwise, the
MAX1601/MAX1604 may interpret this as a start condi­tion. Even when SMBDATA and SMBCLK fall at the
same instant, different fall times for the two signals may
cause the erroneous generation of a start condition. To
ensure that SMBDATA transitions after the falling edge of
SMBCLK, add an RC network to SBMDATA (Figure 6).

1k

VL

0.1µF

VX+5V

MAX1601
MAX1604

Supply Bypassing

Bypass the VY, VX, and 12IN_ inputs with ceramic 0.1µF
capacitors. Bypass the VCC_ and VPP_ outputs with a

0.1µF capacitor for noise reduction and ESD protection.

Power-Up

Apply power to the VL input before any of the switch
inputs. If VX, VY, or 12IN receive power before VL rises
above 2.8V, the supply current may be artificially high
(about 5mA). When the voltage on VL is greater than

2.8V (operating mode), the part consumes its specified
24µA. To avoid power sequencing, diode-OR VX and
VY to VL through a 1kΩ resistor (Figure 5). Take care
not to allow VL to drop below the 2.8V maximum under­voltage lockout threshold.

______________________________________________________________________________________ 15

VY

Figure 5. Powering from Either VX or VY

+5V

CIRRUS LOGIC

CL-PD6730

SMBDATA

SMBCLK

Figure 6. Application with Cirrus Logic Interface

10k
PULL-UP

1.5k

100pF

SMBDATA

MAX1601
MAX1604

SMBCLK

Dual-Channel CardBus and PCMCIA
Power Switches with SMBus™ Serial Interface

__________________Pin Configuration ___________________Chip Information

TOP VIEW

GND

1

N.C.

2

N.C.

3

12INA

4

VPPA

5

VX

VCCA

VX

VCCB

VX

VPPB

MAX1601/MAX1604

12INB

ADR

SMBSUS

MAX1601

6

MAX1604

7
8

9
10
11
12
13
14

28

27
26
25
24
23
22

21

20
19
18
17
16
15

VL
N.C.

N.C.
GND
VCCA
VY
VCCA
VY
VCCB
VY
VCCB
SMBALERT
SMBDATA
SMBCLK

TRANSISTOR COUNT: 4372

SSOP

________________________________________________________Package Information

DIM

A

A1

B

C

α

HE

C

L

D

E
e

H

L

α

INCHES



MIN

0.068

0.002

0.010

0.004

0.205

0.301

0.025

MAX

0.078

0.008

0.015

0.008

SEE VARIATIONS



0.209



0.311

0.037

0˚





8˚

MILLIMETERS

MIN

1.73

0.05

0.25

0.09


5.20

0.65 BSC0.0256 BSC



7.65

0.63

0˚

MAX

1.99

0.21

0.38

0.20


5.38


7.90

0.95

8˚

14
16
20
24
28

INCHES

MIN



0.239

0.239

0.278

0.317

0.397

DIM

PINS

e

SSOP

A

SHRINK

SMALL-OUTLINE

B

A1

PACKAGE



D
D
D
D
D

MAX

0.249

0.249

0.289

0.328

0.407

MILLIMETERS

MAX

MIN

6.33

6.07

6.33

6.07

7.33

7.07

8.33

8.07

10.33

10.07

21-0056A

D

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are

Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.

16

__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

16

__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

16

__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

16

__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

16

__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

16

__________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 [phone]

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.

© 1996 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products.