LPC1837FET256,551 NXP Semiconductors, LPC1837FET256,551 Datasheet - Page 660

• Manufacturer Part Number: LPC1837FET256,551
• Description: Microcontrollers (MCU) 32BIT ARM CORTEX-M3 MCU 136KB SRAM
• Manufacturer: NXP Semiconductors
• Series: LPC18xxr

Specifications of LPC1837FET256,551

• Core: ARM Cortex M3
• Core Processor: ARM® Cortex-M3™
• Core Size: 32-Bit
• Speed: 150MHz
• Connectivity: CAN, EBI/EMI, Ethernet, I²C, Microwire, SD/MMC, SPI, SSI, SSP, UART/USART, USB OTG
• Peripherals: Brown-out Detect/Reset, DMA, I²S, Motor Control PWM, POR, PWM, WDT
• Number Of I /o: 80
• Program Memory Size: 1MB (1M x 8)
• Program Memory Type: FLASH
• Eeprom Size: -
• Ram Size: 136K x 8
• Voltage - Supply (vcc/vdd): 2 V ~ 3.6 V
• Data Converters: A/D 16x10b; D/A 1x10b
• Oscillator Type: Internal
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 256-LBGA
• Lead Free Status / Rohs Status: Details
• Other names: 935293795551

NXP Semiconductors
26.8 Functional description
<Document ID>
User manual
26.8.1 Pulse-width modulation
Each channel of the MCPWM has two outputs, A and B, that can drive a pair of transistors
to switch a controlled point between two power rails. Most of the time the two outputs have
opposite polarity, but a dead-time feature can be enabled (on a per-channel basis) to
delay both signals’ transitions from “passive” to “active” state so that the transistors are
never both turned on simultaneously. In a more general view, the states of each output
pair can be thought of “high”, “low”, and “floating” or “up”, “down”, and “center-off”.
Each channel’s mapping from “active” and “passive” to “high” and “low” is programmable.
After Reset, the three A outputs are passive/low, and the B outputs are active/high.
The MCPWM can perform edge-aligned and center-aligned pulse-width modulation.
Remark: In timer mode, the period of a channel’s modulated MCO outputs is determined
by its Limit register, and the pulse width at the start of the period is determined by its
Match register. If it suits your way of thinking, consider the Limit register to be the “Period
register” and the Match register to be the “Pulse Width register”.
Edge-aligned PWM without dead-time
In this mode the timer TC counts up from 0 to the value in the LIM register. As shown in
Figure
point it changes to “A active”. When the TC matches the Limit register, the MCO state
changes back to “A passive”, and the TC is reset and starts counting up again.
Center-aligned PWM without dead-time
In this mode the timer TC counts up from 0 to the value in the LIM register, then counts
back down to 0 and repeats. As shown in
state is “A passive” until the TC matches the Match register, at which point it changes to “A
active”. When the TC matches the Limit register it starts counting down. When the TC
matches the Match register on the way down, the MCO state changes back to “A passive”.
Fig 74. Edge-aligned PWM waveform without dead time, POLA = 0
74, the MCO state is “A passive” until the TC matches the Match register, at which
MCOB
MCOA
All information provided in this document is subject to legal disclaimers.
0
active
passive
Rev. 00.13 — 20 July 2011
Chapter 26: LPC18xx Motor Control PWM (MOTOCONPWM)
MAT
passive
active
timer reset
LIM
active
passive
Figure
MAT
75, while the timer counts up, the MCO
passive
active
timer reset
LIM
UM10430
© NXP B.V. 2011. All rights reserved.
POLA = 0
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