ST662 STMICROELECTRONICS [STMicroelectronics], ST662 Datasheet - Page 6

• Manufacturer Part Number: ST662
• Description: DC-DC CONVERTER FROM 5V TO 12V, 0.03A FOR FLASH MEMORY PROGRAMMING SUPPLY
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

ST662A
6/12
APPLICATION CIRCUIT
Based on fast charge/discharge of capacitors,
this circuit involves high di/dt values limited only
by R
design due to the need to minimize inductive
paths and place capacitors as close as possible
to the device.
A good layout design is strongly recommended
for noise reason. For best performance, use very
short connections to the capacitors and the
values shown in table 1.
Figure 4: KIT Lay-out
Figure 5: Electrical Schematic
Table 1: List of Components
on
of switches. This implies a critical layout
Charge Pump C1
Charge Pump C2
Decoupling C5
CAPACITOR
O utput C4
Input C3
Electrolyt ic Tantalum
Electrolyt ic Tantalum
C3 and C4 must have low ESR in order to
minimize the output ripple. Their values can be
reduced to 2 F and 1 F, respectively, when
using ceramic capacitors, but must be of 10 F or
larger if aluminium electrolytic are chosen.
C5 must be placed as close to the device as
possible and could be omitted if very low output
noise performance are not required.
Fig 4 and Fig 5 show, respectively, our
EVALUATION kit layout and the relatively
electrical shematic.
Ceramic
Ceramic
Ceramic
TYPE
VALUE ( F)
0.22
0.22
4.7
4.7
0.1