devices:
- AFE
- power & isolation
- ADUM2401 - 3/1 channel magnetic isolator, 5kv isolation.
- original design called for ADUM1301 problem: only 2500V isolation.
- MAX253 - isolated power supply. 8-uMAX (3x5mm) order from Newark; SOIC-8, digikey MAX253ESA+-ND
- LT1425 -- good notes on transformer selection.
- 78250M - choose the 'M' version from mouser -- lower leakage inductance. need V option to meet spec.
- BAT54STA - schottky diode SOT23-3, series.
- digikey 478-3117-2-ND 22uf 10v 0805 tantalum
- 2SK3539 - GP MOSFET, S-MINI-3P
- external interfaces
- Ethernet
- LAN83C185 on the BF537-stamp. not sure if it will run at 3.1V - nothing on the spec sheet - we shall see.
- pulsejack JK0-0025. also on the BF537-stamp.
- USB
- LCD
- Analog
- LM4921 digikey LM4921ITLCT-ND stereo DAC with headphone amplifier output. I2S input. SPI control of volume control and others. suitable for 3V supply. 20-microSMD package. problem: requires 256 x fs sampling clock
- TDA7535 digikey 497-3989-1-ND I2S 20bit sigma-delta DAC with onboard PLL (no external clock required).
- blackfin
devices that can be turned off & on to save power (e.g. actually disconnected from power through a P channel MOSFET. must be careful to tristate all outputs before disabling, otherwise we'll get current through the ESD protection diodes )
- ethernet
- usb reset
- usb host power
- RS 232
- LCD (or at least the 40ma, 6V LED -- the LCD can be disabled in software, and it only consumes 2-3 ma anyway.)
- core voltage boost 0.8v to 1.2V
- AFE
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