19-0598; Rev 3; 2/08
KIT
ATION
EVALU
BLE
AVAILA
10-Port, Constant-Current LED Driver and
I/O Expander with PWM Intensity Control
General Description
The MAX6946/MAX6947 I
2
C-/SMBus -compatible,
serial-interfaced peripherals provide microprocessors
with 10 I/O ports rated to 7V.
Each port can be configured as a 2.5mA to 20mA con-
stant-current LED driver (static or PWM), a 1.25mA to
10mA constant-current LED driver (static or PWM), an
open-drain logic output, or an overvoltage-protected
Schmitt logic input.
Analog and switching LED intensity control includes indi-
vidual 8-bit PWM control per output, individual 1-bit ana-
log current control (half/full scale) per output, and a global
3-bit DAC current control that applies to all LED outputs.
The MAX6946/MAX6947 can stagger the PWM timing of
the 10-port outputs in consecutively phased 45° incre-
ments. Staggering the outputs spreads the PWM load
currents over time in eight steps, helping to even out
the power-supply current and reduce the RMS current.
For a similar part with an SPI
TM
-/QSPI
TM
-/ or MICROWIRE
TM
-
compatible interface, refer to the MAX6966/MAX6967
data sheet.
TM
Features
♦
2.25V to 3.6V Operation
♦
I/O Ports Default to High Impedance (LEDs Off)
on Power-Up
♦
I/O Port Inputs Are Overvoltage Protected to 7V
♦
I/O Port Outputs Are 7V-Rated Open-Drain, 10mA
or 20mA Constant-Current Static/PWM LED
Drivers, or Open-Drain Logic Outputs
♦
I/O Ports Support Hot Insertion
♦
Individual 8-Bit PWM Intensity Control for Each LED
♦
RST
Input Clears Serial Interface and Can Exit
Shutdown (Warm Start)
♦
MAX6946 OSC Input Allows for External PWM
Clock Input
♦
MAX6947 AD0 Input Selects from Two Slave
Addresses
♦
Auto Ramp-Up Out of Shutdown, and Up to 4s
Hold-Off Before Ramp-Down into Shutdown
♦
0.8µA (typ) Shutdown Current
♦
-40°C to +125°C Temperature Range
♦
Tiny WLP Package (4 x 4 Grid)
MAX6946/MAX6947
Applications
Cellular Phones
Portable Equipment
RGB LED Drivers
LCD Backlights
Keypad Backlights
LED Status Indicators
Ordering Information
PART
MAX6946ATE+
MAX6946CAWE+
MAX6947ATE+
PIN-PACKAGE
16 TQFN-EP*
16 WLP
16 TQFN-EP*
PKG
CODE
T1633-4
W162B2-1
T1633-4
Typical Operating Circuit
+3.3V
V
DD
μC
SCL
SDA
SCL
SDA
OSC*
RST
AD0**
GND
*MAX6946 ONLY.
**MAX6947 ONLY.
P0
P1
P2
P3
P4
P5
P6
P7
P8
P9
V
EXT
= +5V
+Denotes
a lead-free package.
*EP
= Exposed pad.
Note:
All devices are specified over the -40°C to +125°C operating
temperature range..
Pin Configurations
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
LOGIC INPUT
TOP VIEW
MAX6946
MAX6947
MAX6946C
A1
RST
B1
P9
A2
VDD
B2
OSC
C2
P7
D2
P5
A3
SCL
B3
P1
C3
P3
D3
GND
A4
SDA
B4
P0
C4
P2
D4
P4
SMBus is a trademark of Intel Corp.
SPI and QSPI are trademarks of Motorola, Inc.
MICROWIRE is a trademark of National Semiconductor Corp.
C1
P8
D1
P6
(BUMPS ON BOTTOM)
16-BUMP, 2.1mm x 2.1mm WLP
Pin Configurations continued at end of data sheet.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
10-Port, Constant-Current LED Driver and
I/O Expander with PWM Intensity Control
MAX6946/MAX6947
ABSOLUTE MAXIMUM RATINGS
VDD to GND .............................................................-0.3V to +4V
SCL, SDA, AD0,
RST,
OSC to GND .........................-0.3V to +6V
P0 to P9 to GND .......................................................-0.3V to +8V
DC Current into P0 to P9 ....................................................24mA
DC Current into SDA ...........................................................10mA
RST
Sink Current.................................................................10mA
Total GND Current ............................................................280mA
Continuous Power Dissipation (T
A
= +70°C)
16-Pin TQFN (derate 14.7mW/°C over +70°C) ..........1176mW
16-Bump WLP (derate 13.3mW/°C over +70°C)........1066mW
Operating Temperature Range (T
MIN
, T
MAX
) ....-40°C to +125°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
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
(V
DD
= 2.25V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
DD
= 3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Operating Supply Voltage
Output Load External Supply
Voltage P0–P9
Power-On-Reset Voltage
Power-On-Reset Voltage Hysteresis
Standby Current Interface Idle
(PWM Disabled, All Ports High
Impedance)
Standby Current in Reset
(PWM Disabled, All Ports High
Impedance)
Supply Current Interface Active
(Reset Run Enabled, PWM
Disabled, All Ports High
Impedance)
SYMBOL
V
DD
V
EXT
V
POR
PORHYS
V
DD
rising
16-pin TQFN
16-bump WLP
RST
at VDD;
f
SCL
= 0Hz; other digital
inputs at VDD or GND
RST
at GND; f
SCL
=
400kHz; other digital
inputs at VDD or GND
f
SCL
= 400kHz; other
digital inputs at VDD or
GND
T
A
= +25°C
T
A
= T
MIN
to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= T
MIN
to +85°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= T
MIN
to +85°C
T
A
= T
MIN
to T
MAX
1.58
50
17
33
1.0
1.3
1.3
1.5
23
24
25
60
62
65
1.8
1.9
2.0
mA
One port set to 20mA
T
A
= +25°C
constant current; all other
ports' output registers set
T
A
= T
MIN
to +85°C
to 0x00, 0x01, or 0xFF;
digital inputs at VDD or
T
A
= T
MIN
to T
MAX
GND
3.2
3.6
3.8
4.0
µA
µA
µA
CONDITIONS
MIN
2.25
TYP
MAX
3.60
7
1.91
128
UNITS
V
V
V
mV
I
STBY
I
RST
I
DD
ΔI
DD10
One port set to 10mA
T
A
= +25°C
constant current; all other
ports' output registers set
T
A
= T
MIN
to +85°C
to 0x00, 0x01, or 0xFF;
digital inputs at VDD or
T
A
= T
MIN
to T
MAX
GND
Delta Supply Current Interface Idle
ΔI
DD20
2
_______________________________________________________________________________________
10-Port, Constant-Current LED Driver and
I/O Expander with PWM Intensity Control
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= 2.25V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
DD
= 3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Input High Voltage
(P0–P9, SDA, SCL,
RST,
AD0, OSC)
Input Low Voltage
(P0–P9, SDA, SCL,
RST,
AD0, OSC)
Input Leakage Current
(P0–P9, SDA, SCL,
RST,
AD0, OSC)
Input Capacitance
(P0–P9, SDA, SCL,
RST,
AD0, OSC)
T
A
= +25°C
10mA Port Nominal Sink Constant
Current (P0–P9)
I
OUT
Output register set to 0x02, T
A
= T
MIN
to +85°C
16-pin TQFN
V
DD
= 3.3V,
V
EXT
- V
LED
= 1V (Note 3) T = T
A
MIN
to +85°C
16-bump WLP
T
A
= +25°C
20mA Port Nominal Sink Constant
Current (P0–P9)
I
OUT
Output register set to 0x02, T
A
= T
MIN
to +85°C
V
DD
= 3.3V,
16-pin TQFN
V
EXT
- V
LED
= 1V (Note 3)
T
A
= T
MIN
to +85°C
16-bump WLP
T
A
= +25°C, V
DD
= 3.3V, V
P0
to V
P9
= 1.4V,
I
OUT
= 20mA
T
A
= +25°C, V
DD
= 3.3V, V
P0
to V
P9
= 1.4V,
I
OUT
= 10mA
Output register set to 0x00,
I
SINK
= 0.5mA
Output register set to 0x00,
V
OLP_
= 5V
From 20% current to 80% current
V
OLSDA
I
SINK
= 6mA
10
2
300
9.3
9.1
9.0
19.00
18.6
18.4
±2.0
±2.0
20
SYMBOL
V
IH
V
IL
I
IH
, I
IL
CONDITIONS
P0–P9: output register set to 0x01
P0–P9: output register set to 0x01
-0.2
10
10
10.5
11.0
11.0
21.12
21.8
22.0
±4.0
%
±5.0
0.5
V
mA
µs
mV
mA
mA
MIN
0.7
x V
DD
0.3
x V
DD
+0.2
TYP
MAX
UNITS
V
V
µA
pF
MAX6946/MAX6947
Port Sink Constant-Current
Matching
ΔI
OUT
Port Logic Output Low Voltage
(P0–P9)
Port Logic Output Low
Short-Circuit Current (P0–P9)
Port Slew Time
Output Low Voltage
(SDA)
V
OLP_
_______________________________________________________________________________________
3
10-Port, Constant-Current LED Driver and
I/O Expander with PWM Intensity Control
MAX6946/MAX6947
TIMING CHARACTERISTICS (Figure 8)
(V
DD
= 2.25V to 3.6V, T
A
= T
MIN
to T
MAX
, unless otherwise noted. Typical values are at V
DD
= 3.3V, T
A
= +25°C.) (Note 1)
PARAMETER
Internal PWM Clock Frequency
External PWM Clock Frequency
Serial-Clock Frequency
Bus Free Time Between a STOP and
a START Condition
Hold Time, (Repeated) START
Condition
Repeated START Condition Setup
Time
STOP Condition Setup Time
Data Hold Time
Data Setup Time
SCL Clock Low Period
SCL Clock High Period
Rise Time of Both SDA and SCL
Signals, Receiving
Fall Time of Both SDA and SCL
Signals, Receiving
Fall Time of SDA Transmitting
Pulse Width of Spike Supressed
Capacitive Load for Each Bus Line
RST
Pulse Width
RST
Rising Edge to
MAX6946/MAX6947 ACK to Cancel
Reset Run
RST
Rising Edge to
MAX6946/MAX6947 ACK to Ensure
Reset Run
SYMBOL
f
INT
f
OSC
f
SCL
t
BUF
t
HD, STA
t
SU, STA
t
SU, STO
t
HD, DAT
t
SU, DAT
t
LOW
t
HIGH
t
R
t
F
t
F, TX
t
SP
C
b
t
W
t
RSTRUN
Reset Run enabled,
internal oscillator
enabled
16-pin TQFN
16-bump WLP
(Notes 4, 5)
(Notes 4, 5)
(Notes 4, 6)
(Note 7)
(Note 4)
0.1
3.0
ms
2.5
(Note 3)
180
1.3
0.7
20
+ 0.1C
b
20
+ 0.1C
b
20
+ 0.1C
b
50
400
300
300
250
1.3
0.6
0.6
0.6
0.9
16-pin TQFN
16-bump WLP
CONDITIONS
MIN
23
20
TYP
32
32
MAX
42
45
100
400
UNITS
kHz
kHz
kHz
µs
µs
µs
µs
µs
ns
µs
µs
ns
ns
ns
ns
pF
µs
t
RSTRUN
Reset Run enabled, internal oscillator
enabled
5.6
ms
Note 1:
All parameters are tested at T
A
= +25°C. Specifications over temperature are guaranteed by design.
Note 2:
Port current is factory trimmed to meet a median sink current of 20mA and 10mA over all ports. The
ΔI
OUT
specification
guarantees current matching between parts.
Note 3:
A master device must provide a hold time of at least 300ns for the SDA signal (referred to V
IL
of the SCL signal) in order to
bridge the undefined region of SCL’s falling edge.
Note 4:
Not production tested. Guaranteed by design.
Note 5:
C
b
= total capacitance of one bus line in picoFarads; tR and tF are measured between 0.3 x V
DD
and 0.7 x V
DD
.
Note 6:
I
SINK
≤
6mA.
Note 7:
Guaranteed by design. Input filters on the SDA and SCL inputs suppress noise spikes of less than 50ns.
4
_______________________________________________________________________________________
10-Port, Constant-Current LED Driver and
I/O Expander with PWM Intensity Control
Typical Operating Characteristics
(T
A
= +25°C, unless otherwise noted.)
STANDBY CURRENT (I
STBY
)
vs. TEMPERATURE
MAX6946/47 toc01
MAX6946/MAX6947
SUPPLY CURRENT (I
DD
)
vs. TEMPERATURE
V
DD
= 3.6V
20
SUPPLY CURRENT (μA)
MAX6946/47 toc02
STANDBY CURRENT (I
RST
)
vs. TEMPERATURE
V
DD
= 3.6V
20
STANDBY CURRENT (μA)
V
DD
= 3.3V
MAX6946/47 toc03
2.0
25
V
DD
= 3.3V
25
1.6
STANDBY CURRENT (μA)
V
DD
= 3.6V
1.2
V
DD
= 3.3V
V
DD
= 2.7V
0.8
15
V
DD
= 2.7V
15
10
10
0.4
V
DD
= 2.25V
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
5
V
DD
= 2.25V
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
5
V
DD
= 2.7V
V
DD
= 2.25V
0
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
DELTA SUPPLY CURRENT (I
DD20
)
vs. TEMPERATURE
MAX6946/47 toc04
DELTA SUPPLY CURRENT (I
DD20
)
vs. TEMPERATURE
V
DD
= 3.6V
DELTA SUPPLY CURRENT (mA)
12
V
DD
= 3.3V
MAX6946/47 toc05
OUTPUT SINKING CURRENT
vs. V
EXT
- V
LED
AT 10mA
12
10
8
6
4
2
0
MAX6946/47 toc06
4.0
15
14
OUTPUT SINKING CURRENT (mA)
DELTA SUPPLY CURRENT (mA)
3.6
V
DD
= 3.6V
3.2
V
DD
= 3.3V
9
2.8
6
2.4
V
DD
= 2.25V
2.0
V
DD
= 2.7V
3
V
DD
= 2.25V
0
V
DD
= 2.7V
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE (°C)
0
1
2
3
V
EXT
- V
LED
(V)
4
5
OUTPUT SINKING CURRENT
vs. V
EXT
- V
LED
AT 20mA
MAX6946/47 toc07
STAGGER PWM PORT WAVEFORMS
(OUTPUT REGISTERS SET TO 0x80)
MAX6946/47 toc08
24
OUTPUT SINKING CURRENT (mA)
20
16
12
8
4
0
0
1
3
V
EXT
- V
LED
(V)
2
4
5
PORT P0
2V/div
PORT P4
2V/div
PORT P7
2V/div
1ms/div
_______________________________________________________________________________________
5
