ISL68227IRAZ datasheet(24/100 Pages) RENESAS

24 / 100 page

ISL68227

5. Temperature Sensing

FN9333 Rev.1.00

Page 24 of 99

Oct.1.20

Temperature Sensing

The ISL68227 monitors internal die temperature and supports external per-rail SPS or NTC resistor temperature

sense using the TEMPn pins. The controller also offers per-phase temperature sense using the CS and CSRTN

pins when paired with select Renesas SPS devices.

5.1

SPS Temperature Sensing

The ISL68227 can be configured to sense SPS temperature on a per-rail or per-phase basis. To configure for

per-rail temperature sense, connect the TOUT/FLT pin of each SPS in the rail together and tie the net to the

ISL68227 TEMPn pin. Select SPS devices also have current sense reference voltage outputs (TREF) that are

proportional to temperature. The ISL68227 can be configured to accept this signal and report individual phase

temperature. When configured for per-phase temperature sense, the SPS TOUT/FLT pins should remain

connected to the ISL68227 TEMPn pin, because the SPS devices report internal fault conditions through the

TOUT/FLT pin. See the typical application diagram (Figure 1 on page 6) for a detailed connection overview of

per-rail temperature sense.

5.2

NTC Temperature Sensing

NTC temperature sensing is used in conjunction with inductor DCR output current sensing to sense the inductor

temperature. In this configuration, the specified NTC is connected to the IC as shown in Figure 16. To avoid noise

problems, the PCB traces leading to the NTC should be routed differentially and kept away from noise sources.

Note: Use the component values shown.

When automatic phase dropping is used in a multiphase design, position the NTC close to the phase that runs in

single-phase operation. For Rail 0, the correct phase is the lowest phase number assigned to the rail as shown in

Figure 17.

Figure 16. NTC Temperature Sense Connection

Figure 17. NTC Placement

ISL68227IRAZ Datasheet(PDF) 24 Page - Renesas Technology Corp