MAX7313ATG-T Maxim Integrated, MAX7313ATG-T Datasheet - Page 17

• Manufacturer Part Number: MAX7313ATG-T
• Description: Interface - I/O Expanders 16-Bit I/O Port Expander
• Manufacturer: Maxim Integrated
• Series: MAX7313r

Specifications of MAX7313ATG-T

• Maximum Operating Frequency: 400 KHz
• Operating Supply Voltage: 2 V to 3.6 V
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• Package / Case: TQFN-24 EP
• Output Current: 50 mA
• Power Dissipation: 761 mW

The 17th output, O16, is controlled through 2 bits in the
configuration register, which provide the same static or
blink control as the other 16 output ports.
The MAX7313 includes an internal oscillator, nominally
32kHz, to generate PWM timing for LED intensity con-
trol or other applications such as PWM trim DACs.
PWM can be disabled entirely for all the outputs. In this
case, all outputs are static and the MAX7313 operating
current is lowest because the internal PWM oscillator is
turned off.
The MAX7313 can be configured to provide any combi-
nation of PWM outputs and glitch-free logic outputs.
Each PWM output has an individual 4-bit intensity con-
trol (Table 14). When all outputs are to be used with the
same PWM setting, the outputs can be controlled
together instead using the global intensity control
(Table 13). Table 10 shows how to set up the MAX7313
to suit a particular application.
The PWM control uses a 240-step PWM period, divided
into 15 master intensity timeslots. Each master intensity
timeslot is divided further into 16 PWM cycles (Figure 11).
The master intensity operates as a gate, allowing the indi-
vidual output settings to be enabled from 1 to 15 timeslots
per PWM period (Figures 12, 13, 14) (Table 13).
Table 8. Blink Phase 0 Registers
Table 9. Blink Phase 1 Registers
Control, Interrupt, and Hot-Insertion Protection
Read back outputs P15–P8 phase 0
Read back outputs P15–P8 phase 1
Read back outputs P7–P0 phase 0
Read back outputs P7–P0 phase 1
Write outputs P15–P8 phase 0
Write outputs P15–P8 phase 1
Write outputs P7–P0 phase 0
Write outputs P7–P0 phase 1
REGISTER
REGISTER
______________________________________________________________________________________
16-Port I/O Expander with LED Intensity
PWM Intensity Control
R/W
R/W
0
1
0
1
0
1
0
1
PWM Timing
ADDRESS
ADDRESS
CODE
(HEX)
CODE
(HEX)
0x02
0x03
0x0A
0x03
OP15
OP15
OP7
OP7
D7
D7
Each output’s individual 4-bit intensity control only
operates during the number of timeslots gated by the
master intensity. The individual controls provide 16
intensity settings from 1/16 through 16/16 (Table 14).
Figures 15, 16, and 17 show examples of individual
intensity control settings. The highest value an individ-
ual or global setting can be set to is 16/16. This setting
forces the output to ignore the master control, and fol-
low the logic level set by the appropriate blink phase
register bit. The output becomes a glitch-free static out-
put with no PWM.
When blink is disabled (Table 7), the blink phase 0 reg-
isters specify each output’s logic level during the PWM
on-time (Table 8). The effect of setting an output’s blink
phase 0 register bit to 0 or 1 is shown in Table 11. With
its output bit set to zero, an LED can be controlled with
16 intensity settings from 1/16th duty through fully on,
but cannot be turned fully off using the PWM intensity
control. With its output bit set to 1, an LED can be con-
trolled with 16 intensity settings from fully off through
15/16th duty.
When blink is enabled (Table 7), the blink phase 0 regis-
ters and blink phase 1 registers specify each output’s
logic level during the PWM on-time during the respective
Using PWM Intensity Controls with Blink Disabled
Using PWM Intensity Controls with Blink Enabled
OP14
OP14
OP6
OP6
D6
D6
OP13
OP13
OP5
OP5
D5
D5
REGISTER DATA
REGISTER DATA
OP12
OP12
OP4
OP4
D4
D4
OP11
OP11
OP3
OP3
D3
D3
OP10
OP10
OP2
OP2
D2
D2
OP1
OP9
OP1
OP9
D1
D1
OP0
OP8
OP0
OP8
D0
D0
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