DC270 Demo Manual: LTC1772 Constant Frequency Current Mode Step-Down DC/DC Converter
Demonstration manual for the DC270 step-down buck regulator using the LTC1772, providing up to 1A at 2.5V from a 2.5V to 9.8V input.
Overview
The DC270 demonstration board is a step-down buck regulator featuring the LTC1772 current mode PWM controller. The circuit drives an external P-channel power MOSFET to deliver a fixed 2.5V output at up to 1A from an input range of 2.5V to 9.8V. Designed for high efficiency and a small footprint, the board utilizes Burst Mode operation for light loads and supports 100% duty cycle for low dropout performance. The document includes detailed performance specifications, a schematic diagram, a full bill of materials, and setup instructions for evaluation.
Use Cases
- Cellular phones
- Portable electronics
- Single or dual Li-Ion cell-powered devices
- Three to six NiCd cell-powered devices
- Noise-sensitive power applications
Topics
Referenced Parts
LR1206-01-R040F
IRC
RCS 1 LR1206-01-R040F 0.040Ω 1% 0.25W 1206 Resistor IRC
LTC1772CS6
Linear Technology
U1 1 LTC1772CS6 6-Pin SOT-23 IC LTC
MBRM120T3
ON Semiconductor
D1 1 MBRM120T3 Schottky Diode ON Semiconductor
CR16-103JM
TAD
RC1 1 CR16-103JM 10k 5% 1/8W 0603 Resistor TAD
CR16-1743FM
TAD
RF1 1 CR16-1743FM 174k 1% 0.1W 0603 Resistor TAD
CR16-8062FM
TAD
RF2 1 CR16-8062FM 80.6k 1% 0.1W 0603 Resistor TAD
JMK212BJ475MG
Taiyo Yuden
CO2 (Optional) 1 JMK212BJ475MG 4.7μF 6.3V Capacitor Taiyo Yuden
LMK325BJ106K-T
Taiyo Yuden
CIN 1 LMK325BJ106K-T 10μF 10V Capacitor Taiyo Yuden
LTC1772
Linear Technology
The exclusive use of surface mount components results in a highly efficient application in a very small board space. It is ideal for cell phones and other portable electronics operating from one or two Li-Ion cells or three to six NiCd cell
CDRH62B
Sumida
Sumida Electric Co. Ltd. CD 43 Series, CDH 53 Series, CDRH62B
| DO1608C-472 | Coilcraft | L1 1 DO1608C-472 4.7μH Inductor Coilcraft |
| FDC638P | Fairchild | M1 1 FDC638P MOSFET Fairchild |
| 6TPA47M | Sanyo | CO1 1 6TPA47M 47μF 6V POSCAP Capacitor Sanyo |
| 06035A221KAT | AVX | CC1 1 06035A221KAT 220pF 10% NPO Capacitor AVX |
| LR1206-01-R040F | IRC | RCS 1 LR1206-01-R040F 0.040Ω 1% 0.25W 1206 Resistor IRC |
| LTC1772CS6 | Linear Technology | U1 1 LTC1772CS6 6-Pin SOT-23 IC LTC |
| MBRM120T3 | ON Semiconductor | D1 1 MBRM120T3 Schottky Diode ON Semiconductor |
| CR16-103JM | TAD | RC1 1 CR16-103JM 10k 5% 1/8W 0603 Resistor TAD |
| CR16-1743FM | TAD | RF1 1 CR16-1743FM 174k 1% 0.1W 0603 Resistor TAD |
| CR16-8062FM | TAD | RF2 1 CR16-8062FM 80.6k 1% 0.1W 0603 Resistor TAD |
| JMK212BJ475MG | Taiyo Yuden | CO2 (Optional) 1 JMK212BJ475MG 4.7μF 6.3V Capacitor Taiyo Yuden |
| LMK325BJ106K-T | Taiyo Yuden | CIN 1 LMK325BJ106K-T 10μF 10V Capacitor Taiyo Yuden |
| LTC1772 | Linear Technology | The exclusive use of surface mount components results in a highly efficient application in a very small board space. It is ideal for cell phones and other portable electronics operating from one or two Li-Ion cells or three to six NiCd cell |
| CDRH62B | Sumida | Sumida Electric Co. Ltd. CD 43 Series, CDH 53 Series, CDRH62B |