Common Emitter: Teardown: Philips HDD070

MP3 player from 2005 with 2 GB hard disk and FM radio. Got 6 pieces of these, all incomplete (without batteries, some case elements and mostly without hard disks).

It received quite a few negative opinions over the internet, mostly related to software and reliability, but inside it is astonishing piece of hardware. Most visible thing would be light but solid case made of AZ91D magnesium alloy (metal surface visible after scratching):

SoC: SAA7750EL

Altera EPM7064AETC100-10, 3.3V EEPROM-based CPLD, ISP via JTAG, 1250 gates, 64 macrocells, working as ATA glue logic circuit

D741649 - TIC hard disk controller

TEA5880 FM tuner

FM tuner (apart from well-known Altera PLD) is worth mentioning. This IC requires only two external components - two coils (top side) that can be also replaced with PCB traces. Coils on the bottom side just filter VCCA and VCCD. It doesn't even require external crystal (the price for this is software calibration requirement). Major drawback seems to be power consumption - according to datasheet 250 mA (typical) to 500 mA (max) from VCCD. That would give 2.5 W power dissipation at VCCD = 5V! Not sure if this is not just print error as it would consume HDD070 battery in 2 or 3 hours.

Top side:

Micron 48LC16M16A2 256-Mbit SDRAM arranged as 4 Mbits x 16 x 4 banks with a

CAS latency of 2 at 100 MHz (see: Using SDRAM on AT91SAM7SE Microcontrollers Atmel Application Note).

Big up and down switches are Panasonic EVQPWBA15 with double-action (to get the idea: one of their recommended application is shutter switch for still camera).

Keypad and headphone remote are using trick with resistance switching - more that one key can be handled by single ADC input.

PCF50605HN, power supply controller - real monster: 3 x DC/DC switching converter, 5 x linear regulator, battery charger and a lot more; produces 1.8V (ARM core), 2.4V (Flash), 3V (wake-up, CPLD, tuner), 3.3V (HDD) and 5V (LCD backlight).