Si9135

Features:

• Up to 95% Efficiency
• 3% Total Regulation (Each Controller)
• 5.5-V to 30-V Input Voltage Range
• 3.3-V, 5-V, and 12-V Outputs
• 200-kHz/300-kHz Low-Noise Frequency Operation
• Precision 3.3-V Reference Output
• 30 mA Linear Regulator Output
• SMBUS Interface
• High Efficiency Pulse Skipping Mode Operation at Light
Load
• Only Three Inductors Required*No Transformer
• LITTLE FOOT® Optimized Output Drivers
• Internal Soft-Start
• Synchronizable
• Minimal External Control Components
• 28-Pin SSOP Package




Pinout






Specifications

V_IN to G_ND . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . -0.3 to +36 V
P_GND to G_ND. . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . ±2 V
V_L to G_ND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 to +6.5 V
BST₃, BST₅, BSTFY to G_ND . . . . . . . . . ... . . . . . . .. . . -0.3 V to +36 V
V_L Short to G_ND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Continuous
LX₃ to BST₃; LX₅ to BST₅; LXFY to BST . . . . . . . . . . . -6.5 V to 0.3 V
Inputs/Outputs to GND
(SYNC, CS₃, CS₅, CSP, CSN) . . . . . . . . . . .. . . . -0.3 V to (VL +0.3 V)
SDA, SCL . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . -0.3 V to +5.5 V
DL3, DL5, DLFY to PGND . . . . . . . . . . . . . . .. . . -0.3 V to (VL +0.3 V)
DH3 to LX₃, DH5 to LX₅,
DHFY to LXFY . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to (BSTX +0.3 V)
Continuous Power Dissipation (TA = 90°C)a
28-Pin SSOP^b . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 572 mW
Operating Temperature Range. . . . . . . . . . . . . . . . . . . . 0°C to 90°C
Storage Temperature Range . . . . . . . . . . . . . . . . . .. -40°C to 125°C
Lead Temperature (Soldering, 10 Sec.) . . . . . . . . . . . . . . . . . 300°C
Notes
a. Device mounted with all leads soldered or welded to PC board.
b. Derate 9.52 mW/°C above 90°C.




Description

The Si9135 is a current-mode PWM and PSM converter controller, with two synchronous buck converters (3.3 V and 5 V) and a flyback (non-isolated buck-boost) converter (12 V). Designed for portable devices, it offers a total five power outputs (three tightly regulated dc/dc converter outputs, a precision 3.3-V reference and a 5-V LDO output). It requires minimum external components and is capable of achieving conversion efficiencies approaching 95%.

Along with the SMBUS interface, the Si9135 provides programmable output selection capability.

The Si9135 is available in a 28-pin SSOP package and specified to operate over the extended commercial (0°C to 90°C) temperature range.