LC-26SB25E/S/RU, LC-32SB25E/S/RU, LC-42SB55E/S/RU 
62  
2.3. U104 (L5985 VFQFPN8) 
2.3.1 Pin Connections and short description 
  
N° 
Type Description 
1 
OUT  Regulator output 
2 
SYNCH  Master/Slave Synchronization. When it is left floating, a signal with a phase shift of half a period respect to the power turn 
on is present at the pin. When connected to an external signal at a frequency higher than the internal one, then the 
device is synchronized by the external signal, with zero phase shift. 
Connecting together the SYNC pin of two devices, the one with higher frequency works as master and the other one as 
slave; so the two power turn on have a phase shift of half a period. 
3 
INH  A logical signal (active high) disable the device. With INH higher than 1.9V the device is OFF and with INH lower than 
0.6V the device is ON. 
4 
COMP  Error Amplifier output to be used for loop frequency compensation 
5 
FB  Feedback input. Connecting the output voltage directly to this pin the output voltage is regulated at 0.6V. To have higher 
regulated voltages an external resistor divider is required from Vout to FB pin. 
6 
F
SW
  The switching frequency can be increased connecting an external resistor from FSW pin and ground. If this pin is left 
floating the deice works at its free-running frequency of 250KHz. 
7 
GND  Ground 
8 
V
CC
  Unregulated DC input voltage 
 
2.4. U351 (HYB18TC256160BF-3S TFBGA-84-55) 
2.4.1 Pin Connections and short description 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Ball#/Pin#  Name  Pin Type  Buffer Type  Function 
Data Signals ×16 Organization 
G8 
DQ0 I/O  SSTL 
G2 
DQ1 I/O  SSTL 
H7 
DQ2 I/O  SSTL 
H3  
DQ3 I/O  SSTL 
H1 DQ4 I/O SSTL 
H9 DQ5 I/O SSTL 
F1 DQ6 I/O SSTL 
F9 DQ7 I/O SSTL 
C8 DQ8 I/O SSTL 
C2 DQ9 I/O SSTL 
D7 DQ10 I/O SSTL 
D3 DQ11 I/O SSTL 
D1 DQ12 I/O SSTL 
D9 DQ13 I/O SSTL 
B1 DQ14 I/O SSTL 
B9 DQ15 I/O SSTL 
Data Signal 15:0 
 
Data Strobe ×16 Organization 
B7 UDQS 
I/O SSTL 
A8 
UDQS 
I/O SSTL 
Data Strobe Upper Byte 
F7 
LDQS 
I/O SSTL 
E8 
LDQS 
I/O SSTL 
Data Strobe Lower Byte 
Data Mask ×16 Organization