Eliza E1 v0 power tree

Date: 2026-05-19 Status: planning. No board exists. No rail is measured. Claim boundary: This document captures the v0 board-level power tree intent. Promotion requires bonded SoC pins, a PMIC binding (package/pmic/da9063.yaml), a charger binding (package/charger/max77860.yaml), a USB-PD binding (package/usb-pd/tps65987.yaml), a fabricated board, and per-rail oscilloscope captures at boot, idle, and worst-case workload.

Source path

USB-C PD source (5..20 V at PPS step 20 mV)
   └─► TPS65987DDH (USB-PD policy engine, sink-first)
         └─► VBUS_RAW (5..20 V, current-limited)
               └─► MAX77860 (charger)
                     ├─► VBAT  (1S Li-ion / Li-polymer 3.0..4.2 V)
                     │     └─► fuel-gauge MAX17260 (separate IC, not in v0 BOM yet)
                     └─► VSYS  (clamped ≥ 3.4 V; PMIC input)
                           └─► DA9063L (main PMIC)
                                 ├─► BUCKCORE  (0.85..1.40 V, ≤2.5 A)  →  AP core (RV64 cluster)
                                 ├─► BUCKPRO   (1.10..1.30 V, ≤2.5 A)  →  NPU core / GPU core
                                 ├─► BUCKMEM   (1.10..1.40 V, ≤2.5 A)  →  LPDDR5X VDD2 (planning) / LPDDR4X VDD2 (v0)
                                 ├─► BUCKPERI  (1.80 V, ≤1.5 A)        →  peripheral 1V8, sensor I2C, audio I2C
                                 ├─► LDO1      (0.6..1.8 V, 100 mA)    →  RTC backup domain
                                 ├─► LDO2      (0.6..1.8 V, 300 mA)    →  AP PLL + SRAM 1V0
                                 ├─► LDO3      (0.9..3.45 V, 300 mA)   →  LPDDR VDDQ
                                 ├─► LDO4      (0.9..3.45 V, 300 mA)   →  DSI AVDD 1V8
                                 ├─► LDO5      (0.9..3.6 V, 300 mA)    →  Sensors 3V0
                                 ├─► LDO6      (0.9..3.6 V, 200 mA)    →  WiFi/BT 3V3
                                 ├─► LDO7      (0.9..3.6 V, 200 mA)    →  Audio codec 3V3
                                 ├─► LDO8      (0.9..3.6 V, 200 mA)    →  Display panel 3V0
                                 ├─► LDO9      (0.9..3.6 V, 200 mA)    →  eMMC 3V3
                                 ├─► LDO10     (1.2..3.6 V, 300 mA)    →  USB PHY 3V3
                                 └─► LDO11     (1.2..3.6 V, 300 mA)    →  GPS / aux 3V3

Rail-by-rail table

Rail	Owner	Voltage (V)	Peak A	Decoupling budget (µF)	Linux power-domain name
VBUS_RAW	USB-PD	5..20	3.0	22 µF bulk + 4× 10 µF MLCC	n/a (charger input only)
VBAT	charger	3.0..4.2	3.0	100 µF bulk near charger	`battery`
VSYS	charger	≥ 3.4	3.0	22 µF bulk + 4× 10 µF MLCC	`vsys`
BUCKCORE	PMIC	0.85..1.40	2.5	2× 22 µF MLCC + 4× 1 µF	`cpu-supply`
BUCKPRO	PMIC	1.10..1.30	2.5	2× 22 µF MLCC + 4× 1 µF	`npu-supply`
BUCKMEM	PMIC	1.10..1.40	2.5	2× 22 µF MLCC + 4× 1 µF	`lpddr-vdd2`
BUCKPERI (1V8)	PMIC	1.80	1.5	22 µF MLCC + 4× 1 µF	`vdd-1v8`
LDO1 (RTC)	PMIC	1.20 (typ)	0.1	1 µF MLCC	`rtc-backup`
LDO2 (PLL)	PMIC	1.00	0.3	4.7 µF MLCC + 100 nF	`vdd-pll-1v0`
LDO3 (LPDDR VDDQ)	PMIC	0.50..0.60	0.3	4.7 µF MLCC + 100 nF	`lpddr-vddq`
LDO4 (DSI AVDD)	PMIC	1.80	0.3	4.7 µF MLCC + 100 nF	`dsi-avdd`
LDO5 (sensors)	PMIC	3.00	0.3	1 µF MLCC	`sensor-3v0`
LDO6 (WiFi/BT)	PMIC	3.30	0.2	4.7 µF + 100 nF	`wifi-3v3`
LDO7 (audio)	PMIC	3.30	0.2	4.7 µF + 100 nF	`audio-3v3`
LDO8 (display)	PMIC	3.00	0.2	1 µF MLCC	`display-3v0`
LDO9 (eMMC)	PMIC	3.30	0.2	4.7 µF + 100 nF	`emmc-3v3`
LDO10 (USB PHY)	PMIC	3.30	0.3	4.7 µF + 100 nF	`usb-phy-3v3`
LDO11 (GPS/aux)	PMIC	3.30	0.3	4.7 µF + 100 nF	`aux-3v3`

Decoupling budgets assume 100 MHz worst-case noise. Real budgets must be re-validated per docs/board/pdn-budget.md using post-layout S-parameter extraction or transient SPICE.

Always-on / wake / sleep domains

RTC backup (LDO1) is on whenever VBAT or USB-PD VBUS is present; it survives hardware power-off. Holds RTC + secure-element NVRAM.
vsys is on whenever VBAT > 3.0 V or VBUS is connected.
All other rails are gated by the PMIC sequencer (docs/security/boot-image-format.md §3 / package/pmic/da9063.yaml#power_sequence).
Wake sources: PMIC PWR button, USB-PD VBUS attach, RTC alarm, WiFi/BT host-wake.

Linux device-tree power-domain mapping (sketch)

This is a planning sketch, not a binding. The generated DTS template under sw/platform/generated/e1-platform.dtsi is the authoritative source once the Linux-capable AP variant lands.

pmic@58 {
    compatible = "dlg,da9063";
    interrupt-parent = <&plic>;
    regulators {
        cpu_supply: bcore { regulator-name = "cpu-supply"; ... };
        npu_supply: bpro  { regulator-name = "npu-supply"; ... };
        lpddr_vdd2: bmem { regulator-name = "lpddr-vdd2"; ... };
        vdd_1v8: bperi    { regulator-name = "vdd-1v8";   ... };
        ...
    };
};

Cross-references

docs/architecture-optimization/phone-platform.md
docs/architecture-optimization/soc-optimized-operating-point.yaml
package/pmic/da9063.yaml
package/charger/max77860.yaml
package/usb-pd/tps65987.yaml
docs/board/pdn-budget.md
research/mobile_platform_2026/02_analysis/pmic_and_charging.md